Cream butter & both sugars with mixer. Add eggs one at a time and mix just until incorporated. Mix in mint extract.
Combine flour, cocoa, salt, baking powder and baking soda in a medium bowl. Add 1/2 cup dry mixture to butter mixture. Blending after each addition just until combined and scraping side of mixer bowl as needed. Remove bowl from mixer, cover and refrigerate for at least 2 hours up to overnight.
Preheat oven to 350 degrees.
Butter hands and roll dough into 1 inch balls. Place on cookie sheet covered with parchment paper.
Bake for 10 minutes. Allow to cool for 5 minutes only. Press one peppermint kiss into the top of each cookie. Move to cookie cooling racks being very careful not to the touch the kiss.
Notes
Based on reader response to this recipe and testing I am modifying this recipe to include 1 cup of butter and more refrigeration time so they do not spread out to far.
