Brown Butter Icing
4 Tb unsalted butter
1 cup sifted confectioners' sugar
1 tsp pure vanilla extract
1 to 2 Tbs milk
1. In a small saucepan, melt butter over medium-high heat until nut-brown in color, about 10 minutes. Remove pan from heat, and pour butter into a bowl, leaving any burned sediment behind.
2. Add sugar, vanilla, and 1 tablespoon milk; stir until smooth. If the icing is too thick, add the remaining tablespoon milk, a little at a time, until consistency is spreadable. Let cool 5 minutes. Use immediately.
The consistency of the icing should be thin enough to spread but not runny.