Cosmic Brownie Cookies
These cosmic brownie cookies are both cute and delicious! A fudgy ultra-chocolatey cookie is topped with ganache and sprinkled with rainbow chips.
A play on the iconic boxed cosmic brownies from the grocery store, these cookies are 100X more delicious (and very easy to make!).
Fudgy Chocolate Cookie Dough
The cookies for these cosmic brownie cookies have intense chocolate flavor and a deliciously rich and fudgy texture.
This is accomplished in two ways:
- A soft and chewy ultra-chocolate cookie dough is enriched with a high ratio of brown sugar to granulated sugar AND involves a hefty amount of cocoa powder to really dial in the chocolate flavor
- The cookies get a slight press right out of the oven (more on this below).
For fail proof results, here’s a reminder that investing in a kitchen scale {aff. link} and weighing your dry ingredients will elevate your baking in so many ways and ensure better outcomes. Always use the weight measures given in a specific recipe versus converting the volume measures to weights with varying online sources since that recipe has been tested with those specific weight amounts.
Why Press the Cookies After Baking?
These cookies will likely come out of the oven slightly domed. That’s a good thing, because we don’t want the cookies to spread and flatten into thin wafers. There would be no joy in that.
Pressing the cookies immediately out of the oven ensures an extra fudgy middle AND creates a surface that is easier to frost and sprinkle.
We aren’t pressing the cookies to smithereens here – just lightly flattening the domed top into an even plateau so the cookies form thick discs of chocolatey goodness.
Cosmic Brownie Frosting
The topping for these decadent chocolate cookies is a simple chocolate ganache. Ganache is just a fancy word for chocolate that is combined with hot cream and stirred until thick and glossy.
Chocolate ganache is very, very rich. And very, very good.
(Spoiler alert: it’s delicious on about a million other things, too, so if you have leftover ganache from this recipe, never fear – slather it on graham crackers or a banana or eat it by the spoonful.)
Once the cookies have cooled, spread a dollop of chocolate ganache evenly across the top, and before the ganache sets, sprinkle with rainbow candy coated chips.
Where to Get Rainbow Candy Coated Chips
Rainbow candy coated chips are the classic colorful garnish on cosmic brownies, and they are so fun and perfect for these cookies, too.
The rainbow chips can easily be found online. I get them here {aff. link}. If the ones at the link aren’t available, just search “rainbow baking chips” online or on Amazon.
If you don’t have rainbow chips on hand, here are a few ideas for what to use instead:
- Mini M&Ms
- Colorful flat sprinkles
- Chocolate jimmies or other colorful sprinkles
- Crisp chocolate pearls
Please Try These Cookies Chilled
These cosmic brownie cookies are exceptionally delicious eaten while the chocolate ganache is still silky and just a bit drippy or once the ganache and fudgy cookie center has set a bit.
But they are phenomenal stored in the refrigerator and eaten chilled. Like, just trust me on this and promise you’ll experience at least one of these cookies that way. SO GOOD.
Brian’s favorite grocery store treat in the history of ever is a cosmic brownie. He has a hidden stash in the pantry. But even he admits that these cosmic brownie cookies are world’s better than his storebought crush.
They are fun and festive for just about any occasion and decadent and delicious enough to fill a need-it-now chocolate craving! I hope you love them…they have quickly become one of my favorite cookies of all time!
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Cosmic Brownie Cookies
Ingredients
- 1 cup (227 g) butter, softened to room temperature (not too soft!)
- 1 ½ cups (318 g) packed light brown sugar
- ½ cup (106 g) granulated sugar
- 1 teaspoon baking powder
- ¾ teaspoon table salt
- ½ teaspoon baking soda
- 2 large (100 g) eggs
- 1 tablespoon vanilla extract
- 2 ¾ cups (390 g) all-purpose flour
- ⅔ cup (57 g) Dutch-process or natural, unsweetened cocoa powder
Topping:
- ½ cup heavy cream
- 1 ½ cups (255 g) semisweet chocolate chips
- Rainbow candy coated mini chocolate chips (see note)
Instructions
- Preheat oven to 350 degrees F (see note!). Line half sheet pans with parchment paper; set aside.
- For the cookies, in a bowl with an electric handheld mixer or in the bowl of a stand mixer fitted with the paddle attachment, cream together the butter, brown sugar, granulated sugar, baking powder, salt and baking soda until the mixture is light and fluffy, 1 to 2 minutes.
- Add the eggs and vanilla. Mix until well-combined, scraping down the sides of the bowl as needed.
- Add the flour and cocoa powder. Mix until evenly combined and no dry streaks remain.
- Scoop the cookie dough into 2-tablespoon size balls and roll until smooth (see note for larger cookies). Place several inches apart on the prepared baking sheets.
- Bake for 10 to 11 minutes until the cookies are lightly puffed and set around the edges but still soft in the center.
- Optional: in my ovens, the cookies are slightly domed on top after baking. Immediately out of the oven, I use a flat-bottomed glass to gently press to an even thickness. Don't smash them flat! Just press the domed top so the cookie is still thick but even across the top. This makes frosting the cookies easier (and prettier) and also gives the cookie an extra fudgy center.
- Let the cookies cool for several minutes on the baking pans and then remove them to a cooling rack to cool completely.
- For the ganache, place the chocolate chips in a medium bowl.
- Heat the heavy cream until steaming and bubbles form around the edges. Pour the cream over the chocolate chips, pressing the chocolate chips to submerge them in the cream. Let sit for 2 to 3 minutes until the chocolate chips are melted and then stir or whisk until the mixture is glossy and smooth.
- Let the ganache cool for 5 to 10 minutes to thicken slightly.
- Frost the cooled cookies with a dollop of ganache and sprinkle with rainbow candy coated chips.
- Serve immediately while the ganache is soft or let the cookies sit at room temperature for an hour or so until the ganache sets. The cookies are delicious served at room temperature and terribly delicious served chilled.
Notes
Recommended Products
Recipe Source: from Mel’s Kitchen Cafe
I made these Finally for 4th of July 2025. My daughter and all of us Love them!! The recipe was spot on for directions and the tip about the glass for getting “cookie dome” gone was so helpful!! My new recipe to make on every occasion. Thank you!
Thanks, Elaine! Happy these worked out well for you!
My daughter loves Cosmic brownies and requested these cookies for her birthday. They were a hit, so yummy! Thanks for the fun recipe!
Thanks, Danielle! Glad it was a hit!
I’m here to report on how much we love these cookies! I’ve made them 3 times in the past couple weeks and everyone who has tried them LOVES them. I can’t get enough of these and I’m pretty sure they’ll be on repeat all summer long! Another rockstar recipe. You never let me down, Mel!!
Angie! I’m thrilled to read that you love these cookies so much. Yay! Thanks for letting me know!
These cookies are a new favorite! I’ve made them twice already. They look so cute with the sprinkles and taste even better. Such a fun recipe!
These are so good! Sooooo good! We didn’t have the sprinkles, so we just left them off. Thank you for a great recipe!
These are divine. Even my harshest critic (teen daughter) loved them! So much better than the store bought brownies. This recipe will be added to the annual Christmas cookie list for sure. Thanks for the recipe. 🤩
Yay! Loved hearing that, Heidi!
Delicious! I baked them as bars in a metal 9×13 pan because I needed to make them for a school event. I checked on them around 24 minutes and they needed a little more time (I had another pan of cookies in the oven, so ymmv on that time). Covered them with mini M&Ms and they’re so festive.
Bars!! What a great idea!
These are so good! I just used the mini M&Ms on top. They were a huge hit!
Thanks for leaving a comment to let me know you liked them, Jen!
Made these today gluten free and they were fabulous! Loved by the celiacs and nonceliacs in my family. I added 1/2 teaspoon of xanthum gum with the baking powder and baking soda. And then swapped the flour for equal parts of gluten free flour (King Arthur brand or my own mix). I did chill the dough for 30-60 minutes before baking since that’s usually more important with gluten free baking. And they turned out delicious!
That’s awesome, Emily! So happy they worked out so well gluten free! Yay!
Thank you for this comment, Emily. Saw this post and knew they needed to be made immediately but am newly gluten free, so making my own swaps is still intimidating. I appreciate you!
Made and they are fantastic! Lactose intolerant so I made the ganache with canned organic coconut milk and it worked fine. Another hit, Mel!
That’s awesome that the coconut milk subbed in well for the cream in the ganache. Thanks for letting us know, Debbie!
I didn’t know it until today, but I’ve been waiting my whole life for this recipe! These cookies definitely bring me back to my childhood, but are way better than the cosmic brownies I used to get in the 90’s! I used whole wheat flour and naturally dyed chocolate chips and they turned out perfect! Mel, you outdid yourself with this recipe!!
Thanks for adding your review, Kimberly! Appreciate it!
Delicious cookies! Usually, I wait a while before trying a recently published recipe. However, that’s not the case with your recipes. I’ve been using many of your recipes since 2011 and I’ve never once had a failure.. I didn’t even bother to read the comments as I knew this recipe as I knew that this recipe would be another hit. I think the cookie would also be great when used to make ice cream sandwiches.
Stephanie – that is the highest praise (and so kind); thank you!! So, so happy you loved these. Kelly, another commenter, made ice cream sandwiches with these and said they were stellar!
These were so quick to make and my kids and I all loved them! Between us and the neighbors, we wiped out half the batch in one sitting! I’ll be making these again for sure.
I definitely would recommend not over-baking them. I had one batch that I left in for about a minute too long, and they weren’t nearly as fudgey. It’s hard to tell when a chocolate cookie is done vs overdone, so watch that time and for a little wiggle in the middle.
I didn’t have the rainbow chips, but mini m&m’s were a great sub! I put them on when everything was still a little warm and they ended up a little melty too. Perfect!
Good insight! I totally agree with you. These are best under baked just slightly. I’m glad the mini M&Ms worked out for colorful topping!
Didn’t make yet
Can they b made one day, eaten the nxt? Or do you hv to eat same day?
They are delicious the next day, too!
Ha! I literally just made cosmic brownies yesterday for the first time without seeing this post. And I also had the thought, I should send this on to Mel. So good and so fun! We loved them — and I’m sure the cookies are awesome. Have a great day & thanks again for all you share!!
Delicious and chocolatey! Made them as is (with the exception of sprinkles instead of rainbow chips, I was too impatient to order them this time), and my family loves them. Today (day 3), I decided to add a little layer of peanut butter on top of the now firm ganache and that was incredible. I definitely will be making these again!
Wow!! The addition of PB on top of the ganache is brilliant!
These were so much fun to make tonight! I bought rainbow sprinkle chips a year ago and have never used them, so when I saw this, I had to jump on it. The brownie cookies are topnotch as is, but then add the ganache and what a fantastic frosting it adds. I’m not usually a sprinkles girl, but the rainbow chips could not make these cookies any better. I love how festive they are and the texture is good, contrary to hard sugary sprinkles. Love this recipe, Mel! Thank you!
Kelly, thanks for leaving a comment on this recipe! And I’m glad you finally found a good use for the rainbow chips!
Oh. My. Goodness. These truly are amazing! I even (don’t hate me Mel, they’re all I had…) used milk chocolate chips for the ganache, and they still were delicious. Fresh or chilled, both are drool worthy.
Haha, I could never hate you, Natalie! So thrilled you loved these cookies. Thanks for letting me know!
So cute and delicious! These cookies have a great depth of flavor.
These are amazing! This made 40 cookies using a #40 cookie scoop, and we used a #60 cookie scoop filled 3/4 full to scoop the ganache on each cookie before spreading. We used pecan cookie pieces (finely cut pecans) sprinkled on top of the ganache, in place of candies. Heath bits would also be great to try. Big hit with my family! Mel is right about eating these chilled—they are worth the wait and are so chewy and delicious! Adding this recipe to our favorite cookies list. Thanks Mel for all your fabulous recipes! Your recipes have changed our lives for the better!
Love the comment and details, Mary – thank you! I’m so happy you loved this recipe. The pecans (and you’re right, heath bits – yum!) sound delish!
I can’t wait to try these!
Also – I have to ask…..have you tried any recipes for a Banana Twin?
My husband loves Cosmic Brownies but he is mourning the demise of the Banana Twins.
I haven’t, but now I’m intrigued!
I haven’t made these yet, but they sure look delicious!
I was wondering if you know if they can be frozen? Would the ganache work being frozen, or would it come out all sticky?
Thank you Mel for always supplying such wonderful recipes! 😍
Hi Lynne, I think they should freeze pretty well. Ganache usually freezes well…but sometimes it can develop little water/condensation droplets on top while thawing.
How do you think these would work for ice cream cookie sandwiches? Do they freeze really hard?
Haven’t tried it myself, but I think they stand a pretty good chance of working well for ice cream sandwiches. Another chocolate cookie that would work really well for ice cream sandwiches are these super soft chocolate sugar cookies: https://www.melskitchencafe.com/soft-chocolate-drop-sugar-cookies/
I made a few of these into ice cream sandwiches and they were bomb dot com. So good.
My husband suggested ice cream sandwiches with this recipe!
So easy & freaking GOOD! My son has already requested them for his bday, which is in October 😆 Made them exactly as written.
So happy these worked out well for you, Ann! And that they were a hit with your son. Thanks for letting me know!
Made them tonight. My 8 year old said we have to have them every night. Fast, easy, totally delicious.
Yay, Courtney! Thanks for letting me know! Smart 8-year old wanting these cookies every night, haha.
what do you think about freezing these? Thinking of a red sprinkle of something on the ganache as some color on the “She’s a smart cookie” cookie table at my daughter’s grad party!
They should freeze great! (Haven’t tried it myself, but all the components are freezable – sometimes ganache can get little water droplets on top after thawing)
Just wondering salted or unsalted butter? I know you usually use salted but wanted to check. Thanks
Yep, salted butter.
What is the best way to store these? Can they be stacked on top of each other?
Once the ganache on the cookies has set (especially if they’re chilled), then yes they can be stacked. If the ganache is soft, it’s best to store them in a single layer.
These look amazing! Can’t wait to try them 🙂
Tried and hubby was ready to eat the cookies without the toppings! LOL. I used mini M&M’s because that’s what I had. I used canned coconut milk to make the ganache and it firmed up fine. I’m lactose intolerant so while I can do a little butter, whipping or heavy cream are definitely out. These came out great!