Preheat oven to 350 degrees F. Rub a 9 inch springform pan all over with butter.
Mix together crust ingredients and press into the bottom and halfway up the sides of the pan. Set it on a baking sheet and bake for 8 minutes. Let cool.
Reduce oven heat to 300 degrees F.
With an electric mixer on medium speed, beat the cream cheese and sugar until smooth.
Add yolks, sour cream, vanilla, and lemon juice; mix until smooth.
Beat egg whites until stiff but not dry, and fold into mixture. Pour over crust and smooth the top.
Set on a baking sheet and bake for 30 minutes at 300 degrees F.
Reduce heat to 250 degrees F. and continue baking for another 30 minutes.
Turn off heat, and let cake remain 1 hr longer with door closed. Open door and let cake remain at least 1/2 hour longer.
Let cool at room temperature, then chill overnight or for at least 8 hours. Top with pie filling if desired.