Cream together the room temperature cream cheese and butter until smooth and creamy.
Add the vanilla and a pinch of salt, then sift in the powdered sugar. You can adjust the amount of powdered sugar to adapt the frosting to your desired consistency. Add more sugar for a thicker frosting or less sugar for a runnier one. You may want to add the powdered sugar gradually until it is the right consistency for you.
Start the mixer on low speed to avoid a cloud of powdered sugar, then gradually increase the speed. For a soft, spreadable frosting, beat on medium speed just until combined and smooth. For a slightly thicker, more pipeable frosting, beat for a few minutes on high speed to incorporate a little bit of air - until thick and smooth.
Notes
The consistency of cream cheese frosting varies greatly depending on the kind of cream cheese you are using. It should be full-fat and ideally the kind that comes in a block - not the soft, spreadable kind in a tub. If you are using cream cheese from a tub, you may need to add more powdered sugar to your frosting to make it firm enough to frost your cupcakes.