In a large bowl, cream together the butter and sugars until light and fluffy. Add in the eggs one at a time, mixing until fully combined. Mix in the vanilla and peppermint extract until fully incorporated.
In a separate bowl, mix together the flour, cocoa powder, baking powder and salt.
Slowly mix the dry ingredients into the wet ingredients until combined. Cover and refrigerate for at least 4 hours.
Preheat the oven to 350℉. Line cookie sheets with parchment paper and set aside.
Add the powdered sugar to a shallow bowl.
Using a medium cookie scoop, scoop the cookie dough into your hands to smooth the surface, then roll in the powdered sugar.
Place the cookie dough balls on the prepared cookie sheet and bake in the preheated oven for 10-12 minutes.
Place a peppermint kiss on top of each cookie. Allow to cool for around 3 minutes on the cookie sheets before transferring to wire racks to cool completely.