Cream Cheese Frosting

This is my mom's excellent recipe for cream cheese frosting. It is the one I always use when I make carrot or pumpkin cake and sometimes I use it for cinnamon rolls as well. It can be doubled or tripled to make as much as you need, although one recipe was enough to completely cover the cake that is shown above.

4 oz. cream cheese
1 tsp. vanilla
1/2 c. butter
2 c. powdered sugar