Preheat oven to 350 degrees. Line 48 mini muffin cups with mini cupcake liners. Whisk together flour, baking powder, and salt in a medium bowl.Advertisement
Stir butter and chocolate in a heatproof mixer bowl over simmering water until melted. Remove from heat; whisk until smooth. Let cool slightly. Return bowl to mixer. Add sugar, and whisk until combined, about 3 minutes. Whisk in eggs, one at a time. Add vanilla. On low speed, stir in flour mixture.
Using a 1 1/4-inch ice cream scoop, place level scoops of batter in cupcake liners. Bake until set, 15 to 16 minutes. Let cool completely before icing.
Spoon icing over cupcakes, covering tops completely. Let set, then decorate with round candies if desired.