Prepare the lemon curd first, allowing it to cool before using. In a large mixing bowl, whisk together the eggs, egg yolks (save the whites for the meringue!) and sugar vigorously for 4 to 5 minutes, until thick and pale. Strain the lemon juice of any pulp and seeds, then add to the mix. Combine the cornstarch and water in a small ramekin, then add the slurry to the mixing bowl.

Pour the mixture into a medium-sized saucepan. Cook the lemon curd over medium heat, stirring constantly with a rubber spatula. Cook for 4 to 6 minutes, until the curd thickens and holds its shape on the back of a spoon. If any clumps form, use a whisk to break them apart. Remove the curd from heat once it's thicken, cover and cool.

Meanwhile, prepare the crust and cheesecake filling. Preheat the oven to 350F/177C and prepare an 8-inch (20-cm) springform pan by double wrapping the bottom and sides of the pan with foil.

For the crust, place approximately 15 to 20 cookies (depends on size) into a food processor and pulse until fine crumbs form; you'll need about 1 1/2 cups of cookie crumbs. Add the melted butter and pulse again until the crumbs are coated. Transfer the crumbs into the prepared pan and use a large spoon or potato masher to press the crumbs until the bottom of the pan, forming an even crust. Bake the crust in the preheated oven for 10 minutes, then remove and cool.

For the cheesecake filling, place the cream cheese into a stand mixer bowl. Mix on medium-high speed for 7 to 9 minutes, scraping down the sides of the mixing bowl often, until the cream cheese is light and fluffy. Add the sour cream or heavy cream, if desired; sugar, and vanilla. Mix again for a few minutes, then add the eggs, one at a time, mixing well after each addition. Scrape down the sides of the mixing bowl often to ensure a smooth batter.

Zest 2 large lemons into the batter, then mix in the zest. To assemble the cake, first pour half of the cheesecake batter over the crust, then add generous dollops of the lemon curd on top. Swirl the curd into the batter using a knife or spoon, then add the remaining cheesecake batter over the top. Repeat the same process with the lemon curd, adding it on top.

Reduce the oven temperature down to 320F/160C. Transfer the cheesecake into a deep baking dish or roasting pan and prepare a water bath. Pour in enough water to cover 1-inch of the pan. Bake the cake at 320F for 1 hour and 30 to 45 minutes, until the center is almost set but still slight wobbly. Turn the oven off and allow the cheesecake to cool in the oven with the oven door cracked open a few inches.