Combine butter and sugar in a large bowl and use an electric mixer to beat until light and fluffy.
Add eggs, one at a time, stirring until completely combined.
Stir in vanilla extract.
In a separate, medium-sized bowl, whisk together the flour, cocoa powder, baking powder, and salt.
Gradually add dry ingredients to wet until completely combined.
Stir in mini chocolate chips.
Cover bowl with plastic wrap and refrigerate at least 4 hours or overnight.
After chilling, preheat oven to 350F (175C).
Roll dough into 1 1/2 Tablespoon-sized balls with your hands and roll thoroughly in powdered sugar.
Transfer to baking sheet and bake on 350F (175C) for 12 minutes.
Allow cookies to cool completely on baking sheet before enjoying.