1 lb. whole milk Ricotta cheese, at room temperature
1 lb. sour cream, at room temperature
2 (8 oz.) pkgs. cream cheese, at room temperature
1 1/2 c. sugar
1/2 c. butter, softened and cut up
3 eggs
3 tbsp. all-purpose flour
3 tbsp. cornstarch
1 1/2 tbsp. vanilla extract

Put Ricotta through sieve or strainer into large mixing bowl and beat together with sour cream and cream cheese until well mixed. Beat in sugar, then butter. Beat eggs in one at a time. Add rest of ingredients and beat until thoroughly blended. Transfer to springform pan, greased and floured very heavily on bottom and sides.

Bake in middle of preheated 300 degree oven 1 1/2 hours; turn off heat and let stay in closed oven 1 hour at least (preferably overnight!). Remove cheesecake from oven and let cool to room temperature.

Slip large plastic food storage bag over top of pan, partly ripping if necessary, and securing; refrigerate overnight. Serve slightly chilled. Serves 10. Don't cut or serve until next day.