3/4 cup butter, softened
1/2 cup white sugar
3 tablespoons all-purpose flour
1 cup packed light brown sugar
2 eggs
1 teaspoon vanilla extract
3 cups crushed cornflakes cereal
1 teaspoon lemon zest
Lightly butter bottom of 9 inch springform pan. Press all of the white on top of crust. Place foil underneath for seal.
In a medium saucepan, beat butter, brown sugar, eggs and vanilla until smooth. Beat in crushed cornflakes cereal, lemon zest and remaining lemon zest. Pour mixture over bottom of crust.
Bake in preheated oven until the top of crust is golden brown, about 1 hour. Cool completely. Cut into squares. Serve immediately.