1 (19 ounce) can vanilla pudding
1 (3.5 ounce) package instant dry mix
1 cup chopped pecans
4 eggs
3 tablespoons lemon juice
1/2 cup milk
1 cup butter, softened
1 teaspoon vanilla extract
1 cup heavy whipping cream
1 1/2 cups whole milk
1 teaspoon lemon zest
Dissolve the pudding mix in 4 cups boiling water. Simmer gently in microwave for 7 minutes, stirring occasionally. Remove from heat. Remove from water slightly and store well cooled.
Beat the egg white and lemon juice into the remaining 1 1/2 cup boiling water; whisk into pudding mixture. Gradually whisk egg yolk into pudding mixture until just incorporated.
Stir whipping cream into pudding mixture creating a thick foam. Fold whipping cream into pudding mixture; pour mixture into pastry shell. Refrigerate for at least 2 hours.
Preheat oven to 375 degrees F (190 degrees C). Brush tops of pastry with lemon zest. Place inside a greased 9x9 inch baking dish.
Bake in preheated oven for 40 minutes, or until pastry is golden brown. Cool on a floured surface; remove from baking dish. Cut into 1/4 inch squares.