Chocolate Frosting

Ingredients

• 1 1/2 pounds semisweet chocolate, finely chopped
• 3 sticks (1 1/2 cups) unsalted butter, room temperature
• 5 cups confectioners' sugar
• 1/3 to 1/2 cup heavy cream

Directions

1. Place the chocolate in a large heat-proof bowl set over (not in) a pan of gently simmering water. Heat until the chocolate is melted, then stir until smooth. 
2. Remove the bowl from the pan and let the chocolate cool to room temperature.
3. In a stand mixer with the paddle attachment, beat the butter and confectioners' sugar on medium speed until light and smooth, about 3 minutes. 
4. Add the melted chocolate and beat until combined. 
5. Add the cream and beat until the frosting is smooth and spreadable.

Notes
Yield: 6 to 8 cups

Source
http://www.foodnetwork.com/recipes/nancy-fuller/orange-ombre-birthday-cake-with-chocolate-frosting.html