In a bowl, beat the cream cheese, eggs, sugar, lemon extract, 1 1/2 teaspoons of lemon zest, and vanilla extract with an electric mixer until light and fluffy.
Spoon the mixture into the graham cracker crust.
Bake the pie in the preheated oven until the filling is set and no longer gooey inside, about 35 minutes.
Remove pie from oven, let stand until it cools to room temperature, and cool in refrigerator until thoroughly chilled, at least 4 hours.
Spread the lemon curd evenly over the top of the cheesecake filling.
Spread the whipped topping over the lemon curd.
Sprinkle the top of the pie with the remaining 1/2 teaspoon of lemon zest. Refrigerate leftovers.