Chocolate Buttercream Icing

I have to admit, I am somewhat of an icing snob. I don't consider buttercream to be genuine if anything other than butter is used. So don't try and fool me!
Chocolate icing has never been my first choice, but being that it is my husband's favorite, I will make it. I discovered this recipe after a search for "best chocolate buttercream" yielded Martha Stewart's website and Billy's Chocolate Buttercream icing. It is very smooth and rich due to the melted chocolate instead of cocoa powder. I have to say, this particular icing has made me a fan. It is delicious!

Ingredients:
2 cups (4 sticks) unsalted BUTTER, softened
12 ounces semisweet chocolate, melted and cooled
1-3 tablespoons of milk
5 cups powdered suger, sifted

1. Sift powdered sugar in a large bowl.
2. In a separate bowl, beat butter until smooth, about 2-3 minutes.
3. With the mixer on low, add chocolate until combined.
4. Mix vanilla in with butter and chocolate mixutre until combined.
4. Start mixing sugar in slowly, one cup at a time, until well combined.
** I add milk at the end, if any at all. I think it depends on the day, the weather and/or the temperature of the butter as to the consistency of your icing. It may be smooth enough that you don't need to add any milk.