Many years ago, I used to bake cheesecakes following a simple recipe in the Sheraton World Cookbook. I obtained a copy of the book recently and tried again. I have made 5 cheesecakes that were 4-5 inches tall and beautiful in the oven. All 5 have fallen however to about an inch think. They fall very quickly after the oven is turned off. I have no idea what is causing this. I've tried variations and read various internet forums. I let the ingredients get to room temperature, try to cut down on beating to reduce aeration, and tried water baths and water pans on a lower rack and without any water. Cooked at both 325 and 350 degrees. I've let it cook in the oven and out and with a small crack open in the oven door In all case, gorgeous cheesecakes in the oven but all fell. The only variances from when I used to successfully make these years ago is that I have a gas oven today and had electric before (I have used a temperature probe to validate the temperature by the way), and I am using a 10 inch round pan as opposed to a 9 inch. All 5 cakes rose about the pan as well. The receipt calls for the following ingredients: 12 oz Cream Cheese 3/4 cup sugar 5 eggs 1 cup half and half 1 cup heavy whipping cream 1/2 teaspoon of vanilla extract 2 teaspoons grated lemon grind 1 tablespoon lemon juice 1. Butter the pan and cover with crushed graham crackers 2. beat cream cheese and sugar 3. add 5 eggs one at a time and beat well after each one. 4. add lemon rind, lemon juice and vanilla extract 5. Add cream and half and half 6. pour into pan 7. place pan in oven in larger pan filled with 1/2 inch of water. 8. Bake 1 1/2 hours at 325 degrees. Any suggestions/advice would be great appreciated.