Beat the butter and sugar together in a bowl. Add egg and vanilla and beat well. Add the flour, cocoa powder, salt, baking soda, and baking powder and stir until smooth. Roll the mixture into 1-inch balls about the size of a walnut (larger if desired). Place on ungreased cookie sheet. Press center of each ball with thumb.
Drain cherries and reserve juice. Place a cherry in indentation of each cookie ball.
In a saucepan, heat condensed milk and chocolate chips until chips are melted. Stir in 4 teaspoons of cherry juice. Spoon about 1 teaspoon of mixture over each cherry and spread to cover cherry. (More cherry juice may be added to keep frosting of spreading consistency.)