Perfect Chocolate Buttercream Frosting

Perfect Chocolate Buttercream Frosting 4 oz. semi-sweet chocolate baking bar, chopped 2 Tablespoons heavy whipping cream 1 1/2 cups butter, room temperature 1/4 cup heavy whipping cream 3 cups powdered sugar 1/4 cup cocoa powder 1/4 teaspoon salt 1 teaspoon espresso powder Place the chopped chocolate bar and 2 tablespoons whipping cream in a bowl and microwave for 30 seconds. Stir until melted. Set aside.  In a mixing bowl, beat the butter for five minutes. Then slowly drizzle in the 1/4 cup of heavy whipping cream and whip until just combined. Scrape down the sides of the bowl, if needed. Sift together the powdered sugar, cocoa powder, salt, and espresso powder. Slowly beat this into the butter/whipping cream mixture. Add the melted semi-sweet chocolate bar mixture, and whip until light and fluffy. If needed, drizzle in another tablespoon or two of whipping cream to make it a better spreading consistency, but do not add too much extra cream, or it will be too thin! Frost the cooled brownies.