Chocolate Snowball Hot Fudge Sauce

In the top of a double boiler set over hot, not simmering, water, heat the chocolate and butter. (Don’t let the bottom of the container touch the water.) Stir often with a silicone spatula until completely melted. Whisk in the cocoa and set aside.

In a small heavy saucepan, heat the sugar and cream over medium heat, stirring until the sugar dissolves. Bring the mixture to the boiling po