Whisk together All-Purpose Flour (2 3/4 cup), Unsweetened Cocoa Powder (1/4 cup), Baking Powder (2 teaspoon), Baking Soda (1/2 teaspoon), and Salt (1/2 teaspoon) together in a medium bowl. Set aside.
Set up the stand mixer with the paddle attachment and combine Butter (1 cup), Dark Brown Sugar (3/4 cup), and Granulated Sugar (1/2 cup) in its bowl. Beat together until fluffy.
Pour in Buttermilk (2 tablespoon), Egg (2), Distilled White Vinegar (1 1/2 teaspoon), Red Food Coloring (1 1/2 teaspoon), and Vanilla Extract (1 teaspoon).
Finally, turn the speed to low and slowly add in the dry ingredients until you have a lovely dough. Cover the bowl and chill the dough in the refrigerator for at least 2-3 hours.
Preheat oven to 325 degrees F (160 degrees C). Line two sheet trays with silicone mats or parchment. Measure the Powdered Confectioners Sugar (1 cup) into a bowl.
Use a 1.5-inch cookie scoop to get perfect mounds of dough, then coat each of them in the powdered sugar before lining them up on the cookie sheet. The first two sheets will accommodate half of the dough, so put the rest back in the refrigerator while you bake the first batch for about 12-13 minutes.
Let the cookies cool before moving them to cooling racks, and repeat the process with the remaining dough. Store in airtight containers and enjoy!