In a large bowl, beat the cream cheese and butter until smooth. Then add the powdered sugar and vanilla, and beat just until combined and fluffy. Do not over mix.
Taste and add a pinch of salt and more vanilla if desired. You can also add 1/2 cup more powdered sugar if you'd like it a little sweeter or thicker.
Store in the refrigerator for 3-5 days.
If using this recipe to pipe on cupcakes, I suggest adding an additional 1-2 cups of powdered sugar and make sure not to soften the butter or cream cheese too much. This will help the frosting hold it's shape.
If you'd like to make chocolate variation, add 1/2 cup of cocoa powder with the sugar and mix until combined.