Ingredients

1 cup graham cracker crumbs2 tablespoons butter, meltedFILLING:2 packages (8 ounces each) reduced-fat cream cheese1 package (8 ounces) fat-free cream cheese1-1/3 cups sugar1/3 cup lemon juice1 tablespoon grated lemon zest3 large eggs, lightly beatenTOPPINGS:1 cup reduced-fat sour cream4 teaspoons plus 1/2 cup sugar, divided1 teaspoon vanilla extract4-1/2 teaspoons cornstarch1/4 teaspoon salt3/4 cup water1 large egg yolk, beaten1/3 cup lemon juice1 tablespoon butter2 teaspoons grated lemon zest

Preparation

Place a 9-in. springform pan coated with cooking spray on a double thickness of heavy-duty foil (about 18 in. square). Securely wrap foil around pan.

In a small bowl, combine cracker crumbs and butter. Press onto the bottom of prepared pan. Place pan on a baking sheet. Bake at 325° until set, 6-9 minutes. Cool on a wire rack.

In a large bowl, beat cream cheeses and sugar until smooth. Beat in lemon juice and zest. Add eggs; beat on low speed just until combined. Pour over crust. Place springform pan in a large baking pan; add 1 in. of hot water to larger pan.

Bake at 325° until center is almost set, 40-45 minutes. Let stand for 5 minutes. Combine the sour cream, 4 teaspoons sugar and vanilla; spread over top of cheesecake. Bake 10 minutes longer.

Remove springform pan from water bath. Cool on a wire rack for 10 minutes. Carefully run a knife around edge of pan to loosen; cool 1 hour longer.

In a small heavy saucepan, combine the cornstarch, salt and remaining sugar. Stir in water until smooth. Cook and stir over medium-high heat until thickened and bubbly. Reduce heat; cook and stir 2 minutes longer. Remove from the heat.

Stir a small amount of hot mixture into egg yolk; return all to the pan, stirring constantly. Bring to a gentle boil; cook and stir 2 minutes longer. Remove from the heat. Gently stir in the lemon juice, butter and lemon zest. Cool to room temperature without stirring.

Spread over cheesecake. Refrigerate overnight. Remove sides of pan.