1/2 cup (113 grams) unsalted butter, room temperature
2 cups (230 grams) confectioners (powdered or icing) sugar, sifted
1 teaspoon pure vanilla extract
1 - 2 tablespoons milk or light cream
Read more: http://www.joyofbaking.com/ChocolateCreamCookiesRecipe.html#ixzz3VHM4scTP