1 and 1/2 cups sugar
1/2 cup plus 1 tbsp cornstarch
1 and 1/2 cups cold water
3 egg yolks, lightly beaten
3 tbsp butter, cubed
2 tsp grated lemon peel
1/2 cup lemon juice
Crust
1 cup all-purpose flour
1 cup finely chopped walnuts
1/2 cup cold butter
In a saucepan, combine sugar and cornstarch; gradually stir in water until smooth. Bring to a boil; cook and stir 1 minute or until thickened. Remove from heat. Stir a small amount of hot filling into egg yolks; return all to pan, stirring constantly. Bring to a gentle boil; cook and stir 1 minute. Remove from heat; stir in butter and lemon peel. Gently stir in lemon juice. Refrigerate until cool.
In a bowl, combine flour and nuts. Cut in butter until mixture resembles coarse crumbs. Press onto the bottom of a greased 13 inch by 9 inch by 2 inch baking dish. Bake at 350 degrees for 15 to 20 minutes or until edges are golden. Cool on wire rack.
In a large mixing bowl, beat cream cheese and confectioners' sugar until smooth; spread over crust. Spread with cooled lemon mixture. In another bowl, whisk milk, pudding mixes and vanilla 2 minutes or until slightly thickened; let stand 2 minutes or until soft-set. Fold in half of the whipped topping. Spread over lemon layer. Spread with remaining topping. Refrigerate for at least 4 hours before cutting.