Line baking sheets with cooking spray or line with silicone liners. Preheat oven to 350 degrees.
Cream butter and sugars in a large bowl. Beat in eggs and vanilla extract.
Sift together the flour, cocoa powder, soda, baking powder, and salt in a medium bowl.
Add the dry ingredients to the creamed mixture and stir until barely combined. Stir in the Andes mint bits.
Scoop dough with a tablespoon (I like to use a cookie scoop), then roll into balls. Place on prepared pans at least 2 inches apart.
Bake at 350° for about 9 minutes. Immediately place a mint on top of each cookie. Let sit for about 5 minutes until the chocolate melts. Use a spoon or offset spatula to spread the melted chocolate over the cookies.
Transfer the cookies to a wire rack to cool completely. It can take up to an hour for the chocolate to set.