Crust: Mix crust ingredients well, fill bottom of spring pan; set aside.

Be sure to bring all the ingredients to room temperature for at least 2 hours. This will make the batter be smoother and help prevent from cracking.

In large mixer bowl beat egg whites on high speed until frothy. Gradually beat in 1/4 cup sugar; continue beating until glossy. Set aside.

In large mixer bowl beat egg yolks until thickened, 3 minutes. Gradually beat in 3/4 cup sugar. Add vanilla extract, sour cream, flour and salt, beat 2 minutes longer. Gradually beat in cream cheeses.

Fold into egg whites just until blended. Do not over mix. Spread batter evenly in spring pan. Put a pan of water on the rack underneath the cheesecake so the top remains moist and helps against cracking. Bake at 325 °F. for 1 hour.

Turn off oven. Run a thin knife around the cheesecake's edge. This will help prevents cracking as it cools down. Leave the oven door slightly ajar after baking and leave the cheesecake in the oven to cool down for 1 hour. Transfer to a baking rack for another 1 hour. Do not jiggle or it will crack. Put in refrigerator over night.