- 3 cups confectioners’ sugar
- 3 tbsp butter
- 1/4 cup plain yogurt or buttermilk
- 1 tablespoon espresso powder
- 1/2 tablespoon hot water
Sift the confectioners’ sugar into a large mixing bowl, and set it aside. In a small saucepan set over medium heat, melt the butter and add the buttermilk or yogurt. Dissolve the espresso powder in the hot water, add to the pan, and bring the mixture just to a boil.
Immediately pour the simmering liquid over the confectioners’ sugar in the bowl, and beat till smooth. Pour over cake while frosting is warm, makes enough to frost a 9 by 13 inch cake or 12 cupcakes (let cool first to spread over cupcakes)
From King Arthur Flour