Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a large mixing bowl, combine unsalted butter, granulated sugar, and brown sugar. Cream together on medium speed until light and fluffy, about 3-4 minutes.

Beat in the egg and peppermint extract until well combined, about 1-2 minutes.

In a separate bowl, whisk together all-purpose flour, cocoa powder, baking powder, and a pinch of salt.

Gradually add the dry ingredients to the wet mixture, stirring gently until just incorporated to avoid overmixing.

Scoop small portions of dough and roll into balls. Place on the prepared baking sheet.

Bake for 10-12 minutes, until edges are set but centers appear soft.

Immediately press a chocolate kiss into the center of each warm cookie.

Allow cookies to cool completely on the baking sheet before transferring them to a wire rack or airtight container.