Ingredients

3 ounces good-quality semisweet chocolate, coarsely chopped 

3/4 cup confectioners' sugar 

1 tablespoon plus 1 teaspoon unsweetened Dutch-process cocoa powder 

1 pinch of salt 

2 ounces cream cheese, room temperature 

6 tablespoons unsalted butter, softened 

1/4 cup sour cream 

Preparation

Melt chocolate in heatproof bowl set over pan of simmering water, stirring occasionally. Let cool slightly.

Sift sugar, cocoa, and salt into a large bowl. Put cream cheese and butter into mixer bowl; mix on medium until fluffy. Reduce speed to low. Add sugar mixture; mix until combined. Mix in melted chocolate and sour cream. Use immediately, or refrigerate airtight up to 2 days; bring to room temperature, and stir before using.