Combine the butter and sugar in the bowl of a stand mixer (or in a large bowl using a hand mixer) and beat together until ingredients are well-creamed. Add eggs, one at a time, mixing until completely combined, and then mix in vanilla extract.
In a separate bowl, whisk together the flour, cocoa powder, baking powder, and salt. Gradually add dry ingredients to your wet ingredients until completely combined.
Cover bowl with plastic wrap and refrigerate at least 4 hours or overnight.
After chilling, preheat oven to 350 degrees Fahrenheit and prepare baking sheet by lining with parchment paper.
Roll dough into 1 1/2 tablespoon-sized balls and roll thoroughly in powdered sugar.
Transfer to baking sheet and bake in a 350 degree oven for 10-12 minutes. Do not overbake!
Within 1-2 minutes of removing cookies from oven, gently press a chocolate kiss into the center of each cookie. Allow cookies to finish cooling completely on baking sheet before enjoying.