Preheat oven to 350 degrees.

In a medium bowl, whisk together flour, cocoa powder, baking powder, baking soda and salt; set aside.

In a large bowl, beat the butter and sugar with an electric mixer, until well combined. Add the egg and vanilla, beat until light and fluffy. Gradually add the flour mixture, beat until well combined.

Shape dough into 1-inch balls and place on an ungreased baking sheet. Press down in the center of each ball with your thumb to create an indentation.

Bake about 10 minutes. Remove to wire rack to cool completely.

Drain maraschino cherries and reserve the juice. Place a cherry in the center of each cookie's indentation.

In a small saucepan, over medium heat, combine the chocolate chips and sweetened condensed milk. Heat until chocolate is melted. Stir in 4 teaspoons of reserved cherry juice.

Spoon about 1 teaspoon of the frosting over each cherry, spreading to cover the cherry fully. If the frosting is too thick, add a little more of the reserved cherry juice to thin it out.