Preheat oven to 350 degrees. In a mixing bowl whisk together flour, baking powder and salt, set aside. In a separate mixing bowl, whisk together granulated sugar, light-brown sugar and cocoa powder. Pour in melted butter and use a wood spoon to stir until combine. Mix in eggs and vanilla extract. Stir in milk. Add dry ingredients and mix just until combine (batter will be thick).

Divide batter among 12 paper lined muffin cups filling each about 2/3 full (about 1/4 cup batter in each). Bake in preheated oven 16 - 20 minutes (lesser for gooier brownies). Allow to cool in muffin tin several minutes before transferring to a wire rack to cool. Cool completely then pipe Marshmallow Frosting over cupcakes and toast edges of frosting with a kitchen torch if desired.

Add egg whites, granulated sugar and cream of tarter to a heat proof bowl of an electric mixer. Set bowl over a saucepan filled with a few inches of simmering water. Heat mixture, whisking constantly until egg whites are warm to the touch and sugar has dissolved, about 3 - 4 minutes. Remove from heat and transfer bowl to electric stand mixer fit with a whisk attachment. Beat mixture beginning on low speed and gradually increasing to high speed, until stiff glossy peaks form, about 5 - 7 minutes.

Tips: Pipe the frosting. Much easier. Top with a toasted crispy marshmallow.