Preheat your oven to 400 degrees
Cube 2 sticks of butter and transfer the cubes into a small bowl. Place the cubed butter into the refrigerator to chill while you gather the remaining ingredients
Combine 1/2 cup of dark baking cocoa, 1 cup of cake flour, 1 1/3 cup of all purpose flour, 1 teaspoon of cornstarch, 3/4 teaspoon of baking soda and 1/2 teaspoon of salt by sifting into a large bowl
In a large bowl with an electric hand mixer or using a stand mixer, cream together 1 cup of brown sugar, 1/2 cup of granulated sugar and the chilled butter until it is light and creamy (3-4 minutes)
Add 2 eggs and continue mixing until they are fully incorporated
Add the dry ingredients 1/3 at a time and mix until combined
Add 1 1/4 cups of peanut butter chips into the dough and mix until evenly distributed
Line a baking sheet with parchment paperĀ
Form dough into balls (from 2 tablespoon to 1/4 cup in size) and place them onto the parchment lined sheet
Once all of the dough has been shaped, chill the dough in the refrigerator for 10 minutes
Spread the chilled dough balls out onto parchment lined baking sheets leaving at least 2 inches between them
Bake for 9-10 minutes or until the edges are set and the centers are still a bit soft
Transfer the cookies still on the baking sheet onto a cooling rack to cool for 10 minutes before transferring them directly onto the cooling rack
Store in an airtight container at room temperature