Melt your butter and unsweetened chocolate in short increments in the microwave, or using a double boiler.
In a large bowl add the powdered sugar, vanilla and the melted chocolate mixture.
Whip together with a stand mixer or hand mixer until all combined.
Add in half of the milk and continue mixing, adding more milk if needed to reach fluffy frosting consistency.
Notes
Calories are automatically generated. For best results calculate based on your exact ingredients.Makes enough to ice one double layer cake or 24 cupcakes.