Preheat the oven to 350 Fahrenheit. Line a baking sheet with parchment paper or a silicone liner, and set aside.
In a large bowl, whisk together the flour, cocoa, baking powder, baking soda, and salt. Set it aside. 2 cups all purpose flour , 3 TBS unsweetened cocoa powder, 1 tsp baking powder, 1 tsp baking soda, 1/2 tsp salt
Combine the butter, brown sugar, and white sugar in a large bowl. Stir together to combine until fluffy. 1/2 cup unsalted butter, 3/4 cup brown sugar, 1/4 cup granulated sugar
Add in the egg and mix until combined. 1 large egg
Add in the buttermilk and vanilla and mix until combined. It may look curdled, that's okay. 3/4 cup Buttermilk , 2 tsp vanilla extract
Slowly add the dry ingredients into the wet ingredients, and mix at a low speed until combined.
Add in the food coloring and mix until you have a nice deep red color throughout. 1 tsp red gel food coloring
Carefully scoop the batter by the 1 1/2 TBS full onto the prepared baking sheet. Keep the batter balls about 2 inches apart, as they well spread while they bake.
Bake the pan in the preheated oven until the "cookie" tops look set and a toothpick can be inserted and comes out clean. Between 9 and 11 minutes.
Let the whoope pies cool on the baking pan for about 5 to 10 minutes, then transfer them to a cooling rack to cool completely.