Chocolate Sour Cream Cupcakes with Chocolate Buttercream

INGREDIENTS

3 oz

unsweetened chocolate, roughly chopped

1 cup

plus 2 tablespoons all-purpose flour

1/3 tsp

baking powder

1/3 tsp

baking soda

1/4 tsp

salt

1/2 cup

unsalted butter, at room temperature

1 1/4 cups

minus 1 tablespoon sugar

eggs

1 tsp

vanilla extract

1/2 cup

sour cream

1/2 cup

water

1 1/2 oz

unsweetened chocolate, roughly chopped

1 1/4 cups

powdered sugar

3 tsp

Dutch process cocoa

3/4 cup

unsalted butter, at room temperature

1/2 tsp

vanilla extract

1/4 cup

heavy whipping cream, at room temperature