Preheat oven to 325F. Lightly spray a 9-inch springform pan with oil. 

To make the crust, combine graham cracker crumbs, sugar, salt, and melted butter until everything is moistened. Press into the prepared pan, going up the sides. (Using a straight sided glass it helpful for pressing it up the sides.) Set aside.

To make the cheesecake, beat softened cream cheese with the whisk attachment of a stand mixer until smooth. Add sugar and beat until combined. Add eggs, one at a time, and vanilla. Beat until well combined and smooth. 

Pour half of the cheesecake batter into the graham cracker crust. Take ¾ cup of the lemon curd and drop spoonfuls over the cheesecake batter. Use a knife to create swirls of lemon curd. Top with remaining batter. 

Bake 45 - 50 minutes or until the cheesecake is set. The very center should still be a bit jiggly but mostly set. Cool to room temperature before refrigerating overnight. 

Before slicing, spread the remaining ¾ cup of lemon curd over top of cheesecake. Top with whipped cream, if desired, right before serving.