Chocolate Cupcakes with Buttercream Frosting

Chocolate Cupcakes
1 1/2 cups all-purpose flour
3/4 cup unsweetened Dutch-process cocoa powder
1 1/2 cups sugar
1 1/2 teaspoons baking soda
3/4 teaspoon baking powder
3/4 teaspoon salt
2 large eggs
3/4 cup buttermilk
3 tablespoons vegetable or canola oil
1 teaspoon vanilla extract
3/4 cup warm water
Mix it all up in a big bowl, spoon it into cupcake tins with paper liners. Set the oven to 350 and bake for 17-20 minutes

Buttercream Frosting
2 cups confectioners' sugar, sifted
4 tablespoons (1/2 stick) unsalted butter, at room temperature
3 tablespoons heavy cream
2 teaspoons vanilla extract
1/2 teaspoon mint extract or 1/4 tsp rum flavoring and an extra 1/4 tsp vanilla
1/2 teaspoon salt
green food coloring(3 drops for my color) or for the purple I did 2 drops blue and 4 drops red 

Chocolate Cupcakes with delicious buttercream frosting, what more really needs to be said?!
The green ones are mint buttercream and the purple are vanilla-rum butter cream.