South of France Lemon Cheesecake

2 lbs. ricotta cheese, drained overnight
2/3 cup sugar
1/3 cup all purpose flour
6 eggs
2 teaspoons orange zest
2 teaspoons lemon zest
1 tablespoon lemon juice
1/4 teaspoon cinnamon
2 teaspoons vanilla

Preheat oven to 300F. Line a 9" springform pan with 3" sides with parchment paper. In a large bowl, stir ricotta cheese with a rubber spatula until creamy. Add sugar and flour, mixing until blended. Add eggs, one at a time, stirring after each addition. Stir in orange and lemon zests, juice, cinnamon and vanilla. Pour into prepared cheesecake pan. Bake for 75 to 90 minutes or until tip of knife inserted in the center comes out clean. Cool on rack for 2 hours. Cover and refrigerate for at least 6 hours before serving. Makes 10-12 servings.