1cup(227g)cold salted butter straight from the fridge, cut into tablespoon-size pieces
1cup(212g)lightly packed light or dark brown sugar
2large eggs, cold from the refrigerator
1 ½cups(213g)all-purpose flour (see note!)
½cup(43g)dark or Dutch-process unsweetened cocoa powder (see note)
1 ½ to 2cups(255 to 340g)semisweet or bittersweet chocolate chips or chunks
Preheat the oven to 375 degrees F. Line two half sheet pans with parchment paper and set aside.
In the bowl of a stand mixer fitted with the paddle attachment, add the cold butter, brown sugar and granulated sugar. Start the mixer on low (the butter will fly around a bit since it's cold) and gradually increase to medium speed. Mix for 4-6 minutes until the mixture is creamy and very well-combined, scraping down the sides and bottom of the bowl as needed.
Add the eggs and vanilla and mix until combined and the batter is light in color, 2-3 minutes. Add the flour, cake flour, cocoa powder, baking soda and salt. Mix on low speed until the dough starts to come together (and so the dry ingredients don't fly everywhere). When just a few dry streaks remain, add the chocolate chips or chunk and mix just until combined and there are no dry spots.
Scoop very large balls of dough (I measured out about 4-4.25 ounces for each cookie) and place several inches apart on the prepared baking sheets. I did five cookies per sheet. Bake for 9-10 minutes until set on the outside but still soft in the middle. Let the cookies rest on the baking sheets to cool for 5-7 minutes before removing. These cookies are amazing warm (with ice cream), chilled, or at room temperature.
Flour: These cookies are meant to be thick and soft - not flat. If cookies tend to flatten more at your elevation (or just in your experience - this can be due to several factors), try adding an additional 1/4 to 1/3 cup flour.Cocoa: I used Hershey's special dark cocoa for this recipe. I highly recommend a dark/Dutch-process cocoa. I haven't tried this recipe with regular, unsweetened cocoa.Butter and Eggs: it's important that the butter and eggs be cold (counterintuitive to most cookie recipes, I know). Just go with it. It takes a while for the butter and sugars to mix together, but it'll happen. It's also a reason a stand mixer is best for this recipe.Tutorial: here's a quick tutorial on making your own cake flour. If using cup measures (instead of weighing the ingredients), don't pack the flour (cake or all-purpose) into the measuring cup. Fluff the flour, scoop in the cup gently and level off.