Melt butter and chocolate in a microwave-safe bowl.
Stir well until smooth and let it cool.
Beat sugar and eggs in a bowl for 2 minutes.
Mix in the melted butter and chocolate mixture.
Add flour, baking powder, and vanilla. Mix until smooth.
Refrigerate the dough for 15 minutes to firm up.
Preheat your oven to 350°F (175°C).
Place powdered sugar in a shallow container.
Scoop 1-inch dough balls and roll in powdered sugar.
Place the sugar-coated balls on a cookie sheet.
Bake for 10 minutes until cookies are set.
Cool the cookies on a wire rack completely before serving.