DIRECTIONS

1. Preheat oven to 350 degrees F (175 degrees C).
2. Mix together the cracker crumbs, sugar, and butter in a bowl until evenly moistened. Press into the bottom and 1/2 inch up the sides of a 9-inch springform pan.
3. In a large bowl, mix together the cream cheese and sugar with an electric mixer until smooth. Blend in the eggs, 1 tablespoon of vanilla, and cream of tartar. Pour over the pie crust.
4. Bake in preheated oven until the center is set, about 50 minutes. Allow to cool on counter for 5 minutes.
5. Mix together the sour cream, 1 teaspoon vanilla, and 1/2 cup sugar in a bowl until smooth; carefully pour over cheesecake starting from the sides of the pan and working your way to the center.
6. Return to oven for another 5 minutes. Allow to cool in pan to room temperature. Refrigerate for at least 6 hours before serving.