Directions:
1.  Crust:  Cream butter, vanilla, and sugar.  Add flour and mix to a dough.  Form a crust by pressing into sides and bottom on an 8 - 9 inch spring-form pan.  

2.  Filling:  Combine ingredients and beat to a smooth mixture.  Pour into crust. 

3.  Topping:  Core and peel apples.  Slice thin and mix with sugar and cinnamon.  Layer on filling.

4.  Bake at 450 degrees for 10 minutes.  Reduce oven to 400 degrees and bake 25 minutes more.