MC's Chocolate Frosting 

1/2 lb bittersweet chocolate
6 1/2 oz unsalted butter
1 tsp espresso powder dissolved in 1 Tbs. hot water
2 tsp vanilla
1 1/2 cups SIFTED powdered sugar (sift into measuring cup)
3 Tbs. unsweetened cocoa powder
5 oz unsalted butter
1/2 tsp salt
1 cup heavy cream

Chop chocolate into small pieces and place in ss bowl with 6 1/2 oz unsalted butter. Put over pan of simmering water. Whisk together as soon as chocolate and butter soften. Keep whisking until just melted and combined. Remove from heat and stir in espresso and vanilla. Cool to room temperature.

Whisk together powdered sugar, cocoa and salt in a bowl.

Place 5 oz of unsalted butter and 1/2 of the powdered sugar mixture in a Cuisinart. Process scraping down sides. Add rest of powdered sugar mixture, start processor and slowly pour in cream. Process for about 10 seconds.

Whisk butter/cocoa mixture together with room temperature chocolate/espresso mixture in a large bowl until it becomes shiny and smooth.

Can be frozen. Bring to room temperature before using.

Plenty for a 9" layer cake.

Source of recipe: Mean Chef