0.5 cup butter unsalted room temperature (1 stick)
0.5 teaspoon vanilla extract
Equipment
bowl
frying pan
sauce pan
oven
knife
whisk
hand mixer
springform pan
Directions
Position rack in center of oven; preheat to 425°F. Butter 9-inch-diameter springform pan with 2-inch-high sides.
Whisk egg yolk, lemon juice, lemon peel and vanilla in small bowl to blend. Blend flour and sugar in processor.
Add butter and process until coarse crumbs form. With machine running, add yolk mixture and blend until moist clumps form. Press dough onto bottom and 1 1/2 inches up sides of prepared pan. Freeze crust 10 minutes.
Whisk egg white until foamy.
Brush crust lightly with some egg white.
Bake until crust is pale golden, about 15 minutes. Cool on rack while preparing filling. Reduce oven temperature to 350°F.for filling: Using electric mixer, beat cream cheese in large bowl until smooth.
Add sugar; beat until well blended. Beat in 2 tablespoons cornstarch, 1 tablespoon lemon juice, all citrus peel and vanilla.
Add eggs 1 at a time, beating just until blended after each addition. Beat in sour cream.
Pour filling into crust.
Bake cake until puffed and cracked around edges and center moves only slightly when pan is gently shaken, about 55 minutes.
Remove from oven. Run small knife around sides of pan to loosen cake. Cool cake in pan on rack. Refrigerate cake overnight.
Boil marmalade and 2 teaspoons lemon juice in saucepan until slightly reduced, about 2 minutes.