Mix flour, cocoa powder, baking powder, and salt. Cream butter and sugar until smooth. Add eggs and vanilla. Mix in food coloring. Add dry ingredients and mix gently until combined. Chill dough for at least 30 minutes. Roll dough into balls and coat generously with powdered sugar. Bake at 350°F for 10–12 minutes until cracked and set on edges. Cool before serving.
Notes
Do not skip chilling. Roll dough heavily in powdered sugar.