Preheat oven to 350°.
In a large mixing bowl, mix flour, sugar, baking powder, and salt.
In a medium mixing bowl, combine melted butter, with cocoa and stir until smooth. Let cool.
Add eggs and vanilla, stir well.
Add to flour mixture. Stir, stir, and stir some more. This takes elbow grease, but it will form into a ball.
Scoop the dough by rounded Tablespoons and roll each ball in confectioners sugar.
Place cookies on a silicone mat on a cookie sheet.
Bake at 350° for 12 minutes.
Remove from the oven and let cool on the pan for 5 minutes before removing to a wire rack.