In a medium bowl stir together flour, baking powder, and salt. In a large mixing bowl of an electric mixer, add the butter and beat. Gradually add granulated sugar.
Add eggs, one at a time, beating well after each addition until combined. Add vanilla. Alternately add flour mixture and milk to butter mixture.
Spoon about 1 tablespoon of the batter into each prepared muffin cup. Sprinkle about 1 teaspoon of the brown sugar mixture over batter in cups.
Cool cupcakes in muffing cups on wire racks for 10 minutes. Remove cupcakes from muffin cups and cool completely on wire racks.
In a large mixing bowl beat butter, vanilla and a dash of salt, add powdered sugar, whipping cream. Until frosting is light and fluffily.
For the topping you can buy or make your own small sized churros. Or you can sprinkle the frosting with a mixture of cinnamon & sugar.