• Adjust your oven rack to the lower 3rd position and preheat your oven to 350°F.
• Prepare the springform pan: Line the bottom of a 9 or 10" springform pan with parchment paper. Spray the inside generously with non-stick spray. Tie a slow-cooker liner tightly around the pan*, and then wrap several layers of heavy-duty aluminum foil around the pan and up the sides.

Make the Graham Cracker Crust:

• Mix the graham cracker crumbs, granulated sugar, and melted butter until combined and add it to the prepared springform pan. Use the bottom of a glass or measuring cup to pack it down tightly and evenly into the bottom of the pan and slightly up the sides. Prebake the crust for 10 minutes.
• Begin boiling water for the water bath.

Make the Cheesecake Filling:

• In a large bowl, use a hand-held mixer to beat the softened cream cheese, granulated sugar, and flour until combined and smooth with no lumps of cream cheese.
• Add the sour cream, fresh-squeezed lemon juice, and vanilla extract and mix until smooth. Make sure there aren't any lumps at this point because you don't want to overmix once you add the eggs.
• Add the room temperature eggs, one at a time, and mix until just combined after each. Once all of the eggs are added mix until smooth, scrape the sides of the bowl with a rubber spatula as needed.
• Pour the filling over the prebaked crust and use a spatula to spread it out evenly. Tap the pan on the counter a few times to release any trapped air bubbles in the filling.

Bake:

• Place the pan inside a large roasting pan with high sides and very carefully pour the boiling water around it, going up about 2" around the sides of the pan. Bake the cheesecake for 1 hour and 10 minutes. Gently shake the pan, it should be set and golden on the outside with a small wobbly center. It will continue to cook as it cools, if it still looks very pale and wobbly all over, continue baking and check again in 5 minutes.
• Turn the oven off and crack the door slightly. Leave the cheesecake in for 1 hour, then remove from the oven and the water bath and let cool at room temperature, then cover and refrigerate overnight so it can fully set.

Make the Lemon Curd:

• Make the lemon curd the next day, after the cheesecake has been refrigerated overnight.
• In a small bowl, whisk the fresh-squeezed lemon juice and flour until the flour is dissolved.
• In a separate bowl, whisk the egg, egg yolks, and granulated sugar until smooth and pale yellow in color.
• Melt the butter in a small pot, add the lemon juice/flour mixture and cook until starting to thicken. Carefully pour the hot liquid into the bowl with the eggs/sugar, and whisk the eggs as you do so they don't curdle. Add everything back to the pot and cook over medium heat, whisking constantly, until very thick.
• Remove from heat and strain the lemon curd through a fine sieve, use a spoon to push it through the sieve and use another (separate) spoon to scrape the strained curd from the other side of the sieve and into a bowl.
• Assemble and serve: Take the cheesecake out of the fridge and remove the sides of the springform pan. Spread the lemon curd all over the top. It's easier to spread if the lemon curd is still warm.
• Use a sharp knife to slice the cheesecake and wipe the knife clean between slices.