- 1 stick butter, melted
- 1 cup dark brown sugar
- 1/4 cup whole milk
- 3 1/4 cups sifted powdered sugar
Stir the sugar into the melted butter. Bring to a boil, stirring, and boil for 1 minutes.
Remove from the heat and stir in the milk. Beat until smooth.
Stir in the sugar.
Spread on cake while still warm.