Grease (or spray w/ nonstick cooking spray) a 10-inch pie dish.
In a mixing bowl, beat together cream cheese, eggs, 1/2 cup sugar and vanilla until creamy. Pour into greased pie dish. Bake at 350 for 25 minutes. Remove from oven and cool for about 10 minutes (Don't turn off oven). In a small bowl, mix together sour cream and 3 Tbsp sugar---pour on top of pie.
Return to 350 degree oven for additional 10 minutes. Cool 1 hour then chill. May top with fresh fruit or pie filling.