Instructions: *Available at some specialty food shops.

Make crust:
In a small bowl stir together wafer crumbs and butter until combined well. Pat crumb mixture onto bottom and 1 inch up side of a 9-inch springform pan and chill crust 30 minutes.

Make filling:
Preheat oven to 300F.

In a bowl with an electric mixer beat cream cheese until light and fluffy. Beat in sugar gradually until mixture is combined well. Beat in sour cream, zest, orange juice, liqueur, salt, and flour. Beat in whole eggs and yolk, 1 at a time, beating well after each addition.

Wrap bottom and side of springform pan with three 14- by 12-inch pieces of foil, 1 at a time, arranging each piece in a different position to make sure foil is at least 1 1/2 inches up side all around. Put pan in a large baking dish and pour filling into crust.

Put dish in middle of oven and with a measuring cup slowly add enough water to it to reach 1/4 inch up side of springform pan, being careful not to let any water inside foil. (Cooling in water bath prevents cheesecake surface from cracking.)

Bake cheesecake 1 hour 15 minutes, or until edges are just set but middle still trembles slightly. Turn off oven and let cheesecake stand 1 hour (cheesecake will continue to set as it stands). Remove dish from oven carefully and transfer cheesecake in pan to a rack to cool completely. Remove foil and chill cheesecake, covered loosely, 6 hours or overnight.

Make glaze:
In a small saucepan melt marmalade over moderate heat, stirring, and cool to warm.

Remove side of springform pan and spread marmalade evenly on top of cheesecake. Chill cheesecake 2 hours (glaze will soften if served at room temperature).

If you would like to email yourself the recipe for later use, or share the recipe with your friends or family, enter the email addresses below and this recipe will be emailed to you and others as well.