adapted from: allrecipies.com
yield: enough frosting for one cake
1/2 cup butter
4 oz unsweetened chocolate
4 cups powdered sugar
1 teaspoon vanilla extract
1/2 cup milk
Melt chocolate and butter in the microwave, or in the top of a double boiler. In a large bowl combine sugar vanilla and 1/2 of the milk. Blend in the chocolate mixture. Whip on medium high setting of mixer with whisk attachment. Add remaining milk a little at a time until desired consistency is achieved.
This printable recipe from StartingtoSimmer.blogspot.com