I am making homemade butter cream icing for my daughter's 1st birthday cake. I am making a large cake for guest and a small cake for her to dive into with her hands. My problem is that when I made the cakes for my first 2 daughters to dive into the icing was kind of a hard crust on top. is there something I am doing wrong when making it. The recipe I use is 2 lbs powdered sugar, 2 sticks butter, 1 cup crisco, 2 tsp vanilla extract and a splash of milk to moisten. I mix it with an electric beater until it is all mixed up. Do I need to mix it longer and add more milk. any help is appreciated. Thank You.

That time of icing is what they call a crusting icing, which means the icing does form a crust on the outside layer. Most powder sugar and butter/crisco based icings will crust, but it does have to do with the ratios of them. The more powder sugar the more it crusts, the more fat the less it crusts. So if you want to adjust your recipe then you can add in a little more fat or take out a little of the powder sugar.

If you are looking for an icing that doesn't crust you want to look at one of the cooked icings like the IMBC or the SMBC. There are some recipes from them in the recipe section.

I don't use butter but when I use 2lbs of powder sugar to 2 cups of crisco, I use about 4 tablespoons (1/4th cup) of liquid in the icing to make a thin consistency. I thicker consistency could make a slightly harder crust.