In a large mixing bowl add cream cheese, ricotta and sugar. Mix well. Add one egg at a time, mixing well after each addition.
Add one heaping tablespoon at a time, mixing well after each addition. Add sour cream and vanilla and mix well.
Line the bottom of a springform pan with wax paper. Grease and flour the wax paper and sides of the pan.
Pour the mixture into the pan and place in the oven to cook for 50 minutes at 350 degrees.
Turn off oven, open the door 1/4 of the way and keep the cheesecake inside the oven for another hour. After the second hour, take the cheesecake out of the oven and place onto the counter to cool for another hour.