Preheat oven to 350 degrees. Line a cookie sheet with parchment paper.
In a microwave safe mixing bowl, melt the chocolate and the butter together until smooth, about 60 seconds. Add the eggs and peppermint extract and stir well to combine.
In a separate bowl, stir together the flour, cocoa powder, baking powder, and 1 1/2 cups powdered sugar. Add the flour mixture to the chocolate and mix well until a soft dough forms.
Place about 1/2 cup additional powdered sugar into a shallow bowl. Dust your palms lightly with the powdered sugar. Using a small cookie scoop, portion the dough into small balls, rolling them in your palms, then coat the balls in powdered sugar. Place the cookies onto the parchment lined baking sheet. Bake for 7-8 minutes. Allow the cookies to cool for 5 minutes before transferring them to a wire rack to cool completely.