Ingredients

2 cups confectioners' sugar 

4 tablespoons (1/2 stick) unsalted butter, melted and cooled 

1/4 cup cocoa powder 

1/4 cup milk 

1/4 teaspoon pure vanilla extract 

Preparation

Place confectioners’ sugar in a medium bowl. Whisk in butter and cocoa powder. Add milk and vanilla, and whisk until well combined.