Beat cream cheese, butter, milk and vanilla in a mixing bowl.
Gradually add the powdered sugar and mix well. Add enough powdered sugar until you have the frosting the consistency you want. I use about 3 1/2 cups.
This will frost a 13 x 9 cake easily as well as about 24 cupcakes. For two layer cakes, you make want to double the recipe, depending on how much frosting you want on your cakes.
To use as a glaze for cakes, use less powdered sugar and add small amounts of milk (use 1 tablespoon to start) at a time until you have the consistency you want as a glaze.