Killer Crunch Brownies
These killer crunch brownies are a brownie explosion! Fudgy brownies, sweet marshmallow cream, and crispy chocolate peanut butter topping.
One of my favorite desserts on the planet, these killer crunch brownies are something special.
Texturally, they are perfect. Fudgy brownie + creamy marshmallow filling + crunchy topping. Seriously, amazing.
But the flavors are spot on delicious, too. The hint of peanut butter in the rice krispie topping is heavenly with the marshmallow and brownie layers.
Rice Krispies for Life
The marshmallow layer in these brownies is good and all, but it’s the crispy peanut butter chocolate layer that is absolutely stellar.
Something about adding that light and airy crunchiness to the top of the rich, soft brownie does something inherently good for my soul.
Easiest Brownies in the World
The brownie base for these killer crunch brownies is from one of my favorite brownie recipes. A bag of chocolate chips, some butter, a bit of sugar and flour is about all you need to make rich, decadent brownies.
It’s the perfect recipe for layering on marshmallow fluff and then the crispy topping.
The recipe makes one 9X13-inch pan of brownies, but it can easily be doubled for a half sheet pan or for two pans of brownies (I mean, why not??).
While the brownies are still warm, right out of the oven, dollop the marshmallow fluff (or creme) over the top in large spoonfuls.
Wait a minute or two and then spread the sticky glorious stuff into an even layer. It’s ok if a tiny bit of the brownie top pulls up into the marshmallow fluff.
It doesn’t have to be perfect, and I promise, regardless of imperfections, these brownies are going to taste amazing.
The crispy topping is just three easy ingredients:
- peanut butter
- chocolate chips
- crisp rice cereal
Melt the peanut butter and chocolate together and stir in the rice krispies. Stir gently so the rice cereal doesn’t disintegrate – but if the PB/chocolate mixture is warm enough, this is a very easy process.
Pile that glorious concoction on top of the marshmallow fluff and use an offset spatula to spread into an even layer.
I like to gently press on the top of this chocolatey cereal layer once it’s spread evenly to compress it just every so slightly.
It should be relatively smooth. As smooth as a rice krispie layer can be.
Killer Crunch Brownies
Once you experience these killer crunch brownies, I’m just warning you that it’s hard to go back to every day brownies again.
They are unique and just different enough to be super appealing…while not being so *out there* that they make people feel uncomfortable (you know what I mean?).
Every time I make these for a potluck or gathering, they are one of the first things to go. They are a showstopper and rightly so. They taste even more amazing than they look!
Killer Crunch Brownies
- 1 (12-ounce) bag (340 g) chocolate chips, (2 cups)
- 1 cup (227 g) butter
- 1 ½ cups (318 g) granulated sugar
- 1 teaspoon vanilla
- 4 large eggs
- 1 ½ cups (213 g) all-purpose flour
- ½ teaspoon salt
- 1 (7-ounce) jar (198 g) marshmallow crème
- 1 cup (255 g) peanut butter
- 1 cup (170 g) semi-sweet chocolate chips
- 3 cups rice krispie cereal
- Preheat the oven to 350 degrees. Line a 9X13-inch baking pan with aluminum foil or parchment paper and lightly spray with cooking spray (helps with cleanup and lifting out the bars).
- For the brownies, in a medium saucepan over low heat or in a microwave-safe bowl in the microwave, melt the butter and chocolate chips. Stir constantly and remove from the heat when the chips are fully melted.
- Whisk in the sugar and vanilla. Add the eggs, blending fully, one at a time. Add the flour and salt and mix until well combined. Pour the batter into the prepared pan. Bake for 25-30 minutes until the brownies are cooked through and set but not overbaked.
- While the brownies are still warm, dollop the marshmallow crème over the top in large scoops and spread into an even layer.
- In a medium saucepan or in a microwave-safe bowl in the microwave, melt the peanut butter and chocolate chips together over low heat, stirring constantly, until melted and smooth. Remove from the heat and stir in the rice krispies until evenly coated.
- Scoop spoonfuls of the crispy topping over the marshmallow layer and gently spread into an even layer. Let the pan of brownies cool to room temperature and then refrigerate until the chocolate krispie topping is set, 1-2 hours. Serve chilled or at room temp.
Recipe Source: adapted from a recipe Katie S. (who works at the company my husband used to work at) sent me a couple of years ago
Recipe originally posted Dec 2012; updated March 2021 with new pictures, recipe notes, etc.
56 Comments on “Killer Crunch Brownies”
So good!!! This recipe has been on my list for so long and I’ve never gotten around to trying it, oh goodness, so glad I finally did! YUM! My family loved it! Can’t wait to make them again.
So this is the recipe that got me to my first comment on Mel’s Kitchen Cafe. These are stellar. Wow. Have made it into my top recipes for brownies (that’s pretty hard). Everything about them is spot on.
I also just melted mini marshmallows on the stove top and smeared them on and it worked very well.
These were REALLY good, I think I have eaten almost the whole pan alone. I didn’t have marshmallow fluff so used marshmallows and put them in the oven for a few minutes to soften them then added the topping as directed.
Mmmm good! Thanks for sharing another great recipe. These were a big hit with my boys. The pan didn’t last the night 🙂
Does this freeze well?
I just made these today, and they are out of this world! The brownie layer is super fudgy, and I like the marshmallow cream. And my kids love the Rice Krispies with peanut butter and chocolate on top. Seriously so so good!!
I haven’t tried freezing these, so I’m not sure. Sorry!
I’ve made these brownies for years and anyone who has ever tried them,
absolutely loves them. Instead of marshmallow cream, I’ve always used miniature marshmallows. You just completely cover the top of the brownies with the marshmallows, stick the pan back in the oven for a minute or two (they puff up a bit) and then let it sit while you make the rest of the topping.
Will the top layer adhere to brownie layer without the marshmallow fluff layer? I’d like to try it without that sticky layer for a less messy kids’ snack.
I don’t think it will stick quite as well without the marshmallow layer.
I doubled the recipe and baked it in a half sheet jelly roll pan (13×18). This was my first time making these brownies so I have nothing to compare them to, but I was very happy with how they turned out. I did bake them a little longer- 33 minutes. They came out nice and fudgy, but still held their shape. Thanks for the killer recipe!
Made these and they are delicious! Do you think the leftovers need to stay refrigerated?
Yes, I usually refrigerate any leftovers but you probably don’t need to if your house is on the cool side (not overly warm).
My grandma made a brownie similar to these, and I have not been able to replicate the crispy peanut butter frosting! I CAN’T wait make these! I’m so excited. Thanks so much!!
Unreal. My sister tasted them and I cannot repeat what she said!! So happy I made these. Have already shared with fam and friends. Simply unbelievable.
Hey Mel- I grew up with these bars. We called them Rocky Road brownies. Delish!
Mel, I cannot wait to make these. Thank you for sharing them again on the newsletter!
I made these last week for a progressive dinner that I hosted and we all LOVED them!!! The texture of them is amazing! Amazingly they didn’t all get eaten so I popped them in the freezer to keep! Let me tell you, still delicious!! Thanks again for another fantastic recipe!
Could this be doubled for a jelly roll size pan?
Are you talking about a large, rimmed baking sheet (like 11X17-inches or similar sized)? I think it should work but I haven’t tried it that way before.
You need a super hero name:)
I needed a dessert for my daughter’s team party, this one fit the bill. So, easy to make and assemble, since I only had an hour. She came home with an empty dish and raves.
Thanks for coming to my rescue.
Hi Mel! So I wanted to let you know that my friends and I follow you, almost exclusively, for recipe ideas. I have tried almost every one and they’re always a hit with my family and friends. You have a huge following in Baraboo, WI! In high school my cross country coach’s Killer Crunch Bars were legendary. The food champions were made of! In a recent try to find them I hadn’t seen anything close but when I found them on your site I was shocked! Even more when I realized you’re from the Green Bay area and so was she and her whole family! Perhaps word has gotten around about their amazingness and your hubby’s co-worker recieved the recipe too. Thanks again!
Thanks Mel for your quick reply.
I am baking this for a friend who will be celebrating her wedding anniversary tomorrow.
Btw, I come from Cebu City, Philippines.
Hello Mel. I came across your blog searching for extraordinary recipes. Thank you for sharing.
The 1 pack chocolate chips is equivalent to how many cups?
I get my chips in kilo bags and would like to be precise in my measurements when i bake this Killer Brownies.
Maris – one package of chocolate chip is 2 cups.
Anyone ever try crunchy peanut butter instead of regular?
I made these over the weekend and HOLY MAN!! I love them, my kids love them. I had to box up half of the pan and give it away because I knew we would EAT THEM ALL!!! Rich, decadent, easy recipe. No crazy ingredients. I know I will have to make them again, but who can I “force” some of these on next just to not have them in the house??
Wow! The way the textures (crunchy, soft, smooth, creamy) and flavors all come together is nothing short of amazing! They really lived up to their name! I had no marshmallow fluff, so I found a recipe here: http://www.food.com/recipe/fantastic-marshmallow-fluff-clone-75813. I found that 1/3 of the recipe made 8 ounces of fluff (in a mixing bowl beat 1 egg white, 2/3 cup corn syrup, and a pinch of salt for 5 minutes or until doubled in size; then add 2/3 cup powdered sugar and 1 tsp. vanilla until well blended). It worked like a charm and I couldn’t believe how easy it was. I don’t think I’ll ever buy marshmallow fluff again. Anyway, I just thought I’d pass that on. Oh, and thanks Mel for such a great blog! I especially appreciate how kind you are to all who comment. Not all food bloggers are.
These are good. So. So. So. Soo so sosoosososoosos good. Actually, they are amazing. AH! I love you, Mel! They were good immediately out of the oven and chilled over night in the fridge. Thanks for the awesome recipes!
I made dinner for a family from church and brought a plate of these. I thought they were good but almost too rich and peanuty. I could only eat one and had to cut into tiny squares. I wasn’t sure if I would make again. Then, I brought some into work the next day and I think the flavors had melded into some kind of fabulousness because I liked them much, much better and couldn’t stop trying “just one more bite.” In the future, I will make them a day ahead.That is actually helpful if you need to bring treats somewhere and want to make ahead. They were still just as moist and soft.
Denise – no, I used regular rice krispies.
Did you use Cocoa Krispies?
Ok, i made these last night and took the brownies out before they were set, and when i put the marshmallow on top i could tell i had to put them back in to cook a few min. more with the marshmallow allready on top and they still turned out great!! LOVE these : ) i also used dark chocolate morsels for the top part!
I made these for my husband’s work party and they were a hit! Now to get more marshmallow creme so I can make more for my kids. Maybe this time they will get more than the crumbs.
These are phenomenal. The crunchy cereal with the gooey brownie is amazing and the flavour combination is perfect.
YEY! So glad you stumbled across the recipe I sent you from 2 yrs ago 😉
Happy to hear they were a hit. They are pretty darn fantastic!
i love crunch bars and i love brownies. using rice krispies in a crunchy layer is really quite brilliant and i’m glad someone thought of it!
I have made these with biscoff in place of the peanut butter (my son has a peanut allergy) and they were wonderful!
We love these and have for many years the cereal freeze’s well!
Made them with Michelle and grandkids today. We loved them. We did substitute semi for milk chocolate though. I don’t do dark chocolate in any way shape or form. Will definitely be making these again.
I had to comment because I just made these for my daughter’s Bible study group tonight. I had all the ingredients and I couldn’t resist. I only kept one small piece for myself…too tempting….and I have to say they are really good – delicious and rich.
I’ve been making a version of these for 20+ years! They are great, and great to take. They always get rave reviews.
I have almost the same recipe from Betty Crocker…only you use frosting instead of marshmallows and you add peanuts. SO good! I’m gonna have to try it with marshmallow creme and sans peanuts since I somehow have that and not frosting. 😉
These will definitely be a hit in my house!
I have made these delicious brownies for years and they are loved by all!! If you don’t have marshmallow creme, you can sprinkle mini marshmallows over the top in the last couple minutes of brownie cooking time until they get soft and puffy. Then proceed. JUst a tip to use in a pinch.
Keri – yes, I use semisweet or bittersweet.
Kim- as you know, many baked treats freeze perfectly; although I haven’t tried freezing these, I am skeptical on how they would fare thanks to the cereal mixture on top.
Erin – I know many who are allergic to peanut butter sub soy butter or sunbutter (from sunflower seeds).
For the brownies, do you use semi-sweet chocolate chips?
I have been making these for years, they are the best brownies ever!
These indeed do look killer, as I’m allergic to peanut butter (and other nuts)! Any ideas for an alternative? Would caramel be too sweet? What about making chocolate rice crispy treats for the top?
My daughter has a Christmas event coming up and I’m thinkin’ these are going to be PERFECT!!!! Thanks for posting this! Merry Christmas! EMichelle
Yes, these look absolutely killer… killer to the size of my butt!
I am hypnotizing myself as I type this to forget about this recipe before I make and inhale the entire pan by myself.
So I love the combination of peanut butter and marshmallow fluff. Any recipe with those two ingredients is a winner in my book! These look absolutely amazing. And I love how you add rice krispie cereal to give it some texture and crunch. Pinning this to my “need to make asap” board 🙂
You are “killing” me with all of these awesome desserts, Mel! Everytime I decide which one I am going to make to give away as gifts, you post another amazing recipe that I want to make! These brownies sound incredible. I think I’m going to wait until Sugar Rush 2012 is over before I make my final decision on which treat to make! Another thought I have is to make them all and freeze them, but I’m not sure how some of them (like these brownies) would freeze. Any thoughts? Thanks!
These do sound “killer!”