• Preheat the oven to 350℉.
• In a medium bowl, mix together graham cracker crumbs, 5 Tablespoons butter and 1/4 cup sugar until well combined.
• Using the flat bottom of a small measuring cup, press the crust in an even layer into the bottom of a 9-inch springform pan. Bake 5 minutes. Transfer to a baking sheet and let cool.

Cheesecake Layer

• Using an electric mixer or a stand mixer fitted with a paddle attachment, beat together 3, 8-ounce packages softened cream cheese with 1 cup sugar on medium speed until smooth. Stir in 4 eggs, lemon zest and 1 teaspoon vanilla. Beat 2 minutes, or until smooth and creamy. Pour over cooled crust. Tap on the counter to make it even.
• Bake 40-50 minutes, or until the edges have puffed slightly and barely starting to brown. The center should be baked to the touch but still wiggle a bit.
• Let cool on top of the oven 10 minutes before using a knife to run along the inside of the pan to loosen the crust and help prevent cracking as the cheesecake cools. Do not remove the ring from the pan. Let cool to room temperature then chill for at least 7 1/2 hours up to overnight.
• After the cheesecake has chilled, remove from springform pan then spread the lemon curd over the top. Add whipped cream if desired.