Why are cakes from the grocery store so delicious? It's in the frosting. This easy, homemade grocery store frosting recipe delivers the same sweet, smooth flavor of a store-bought cake.
In the bowl of a standing mixer or in a large bowl with an electric hand mixer, blend the butter and shortening on low speed.
Gradually add about half of the confectioner's sugar. Keep the mixer on low when adding additional ingredients, but you may increase the speed to medium when blending.
Blend in the vanilla, salt and four tablespoons of the milk or water.
Gradually add the rest of the confectioner's sugar and mix very well until the frosting is smooth. If necessary, add additional milk or water to desired consistency.