To make the no bake graham cracker crust, stir together the graham cracker crumbs, sugar and melted butter. Press firmly into a 9 x 13 inch pan and set aside.
Add the cream cheese, powdered sugar, vanilla, lemon juice and sour cream to the bowl of a stand mixer. Beat on medium speed for a minute or two until smooth and combined, scrape down the sides with a spatula as needed.
If you choose to use cool whip, gently fold in 16 ounces of cool whip into the cream cheese mixture with a spatula.
If you choose to use heavy whipping cream, add 2 cups of heavy cream to the cream cheese mixture and beat on high for 2-3 minutes until thickened and air is incorporated. Scrape down the sides of the bowl as needed. Only try this if you have a stand mixer. If not, beat the heavy cream until stiff peaks form and then gently fold into the cheesecake mixture with a rubber spatula.
Gently spread the mixture over the graham cracker crust. Cover and chill in the refrigerator for at least 4 hours until set. Chilling overnight is best.
Serve with your favorite cheesecake toppings. This will keep in the refrigerator for 5 days.