2 lb. powdered sugar
2 c. butter
1 c. white shortening (Crisco)
1/2 c. non-instant powdered milk
1/2 c. milk (more or less)
1 tsp. salt
1 tsp. butter flavor
1 tsp. vanilla (use clear flavoring if making very white frosting)

Substitute white shortening if you want your favorite really white.

This mixes really well with food processor otherwise use very heavy duty mixture. Color with food colorings if desired.