In a large bowl beat the softened cream cheese until smooth and creamy with a mixer. Add the softened butter to the bowl and beat for 1-2 minutes or until the butter is completely combined with the cream cheese.
Add the egg and the vanilla extract to the mixing bowl and beat for 3 minutes. Slowly add the sifted powdered sugar to the bowl and beat on low until combined well. Then beat on high for 2 to 3 minutes or until light and fluffy.
If making an 8 or 9 inch baked cheesecake immediately spread the cheesecake filling into an unbaked graham cracker crust. Place the cheesecake on a baking sheet.
Bake for 30 minutes in a preheated 350 F. degree oven. Let cool on cooking rack at least 3 hours or overnight before serving.