Creamy Lemon Pudding Cheesecake

Preheat the oven to 325°F (163°C). In a medium bowl, combine the graham cracker crumbs and melted butter. Press the mixture into the bottom of a 9-inch (23 cm) springform pan. In a large bowl, beat the cream cheese and granulated sugar until smooth. Add the lemon juice, lemon zest, and vanilla extract, and mix well. Add the eggs one at a time, beating well after each addition. Stir in the cornstarch. Pour the cream cheese mixture over the crust in the springform pan. Bake for 45 minutes, or until the center is set and the top is lightly golden. Remove from the oven and let cool in the pan for 10 minutes. Run a knife around the edge of the pan to loosen the cheesecake, then remove the sides of the pan. Let the cheesecake cool completely, then refrigerate for at least 2 hours, or overnight. In a chilled bowl, beat the heavy cream and powdered sugar until stiff peaks form. Serve the cheesecake topped with the whipped cream.