227g (1 cup) unsalted butter, softened at room temperature
250g (2 cups) powdered sugar
7 milliliters (1/2 tablespoon) vanilla extract
1g (1/8 teaspoon) salt
125g dark chocolate (I used 72%), melted and slightly cooled
60 milliliters (1/4 cup) heavy whipping cream
Instructions
In the bowl of an electric mixer with a paddle attachment, beat butter and powdered sugar on low speed for one minute
Add vanilla and salt; beat on low just for thirty seconds or well until combined
Add the melted chocolate and beat on medium speed for about two minutes or until smooth; scrape the sides of the bowl with a a rubber spatula
Add whipping cream and beat on medium-high speed for one minute
Use a flat metal spatula to frost the top and outside of cake; serve immediately or chill in refrigerator and bring to room temperature about an hour before serving