Use this to frost our Six-Layer Chocolate Cake.
Sift sugar, cocoa, and salt together into a bowl; set aside. Put cream cheese and butter in the bowl of an electric mixer fitted with the paddle attachment. Mix on medium speed until smooth.
Reduce speed to low; gradually mix in sugar mixture. Pour in melted chocolate in a slow, steady stream. Gradually mix in creme fraiche.
Frosting can be refrigerated, in an airtight container, up to 3 days. Just before using, bring to room temperature; beat until smooth.
