Crust
3/4 cup cookie or graham cracker crumbs
2 tablespoons granulated sugar
3 tablespoons melted butter

Filling
16 ounces cream cheese (regular or lite)
2/3 cup granulated sugar
2 eggs
1 egg yolk
1/4 cup frozen orange juice concentrate, thawed
1 teaspoon orange or lemon zest or dried grated rind
1 tablespoon all-purpose flour
1/2 teaspoon vanilla extract

Combine crumbs with sugar; mix in melted butter until well moistened. Pat into a 7-inch springform pan.

In a medium bowl, cream together the cream cheese and sugar. Add eggs and yolk and beat for about 3 minutes on medium with a hand-held electric mixer. Beat in orange juice, zest, flour, and vanilla. Beat for another 2 minutes. Pour batter into prepared crust; place on a rack or aluminum foil ring in a crockpot (so it doesn't rest on the bottom of the pot). Cover and cook on HIGH for 2 1/2 to 3 hours. Turn off and leave for 1 to 2 hours, until cool enough to remove.

Cool completely and remove the sides of the pan. Chill before serving, and store leftovers in the refrigerator.