Zest the lemons into a medium sized glass bowl and set a fine-mesh strainer on top.
Whisk the eggs, egg yolks and sugar in a small glass bowl that fits over a pot filled with a few inches of water. Bring it to a low simmer and place the bowl on top.
Whisk the eggs constantly, trying not to splash the mixture up onto the sides*. Whisk until mixture has thickened, coats the tines of the whisk, and reaches about 170°F.
Remove the lemon curd from heat and stir in butter one tablespoon at a time, stirring each time until fully incorporated.
Stir in the lemon juice and immediately transfer the mixture to the fine-mesh strainer. Strain into a bowl and let cool for at least 10 minutes before covering and transferring to the fridge to chill.
Meyer Lemon Cheesecake
Preheat oven to 375°F.
Rub the inside of a 9-inch springform pan with butter until lightly coated. Stir together the graham crackers and melted butter and use the bottom of a measuring cup to press it into the bottom of the pan.*
Bake for 8-10 minutes or until fragrant and golden brown. Let cool completely.
Change the oven temperature to 350°F and set the wire rack into the lower third of the oven.
Place two long sheets of aluminum foil in a cross shape on your work surface. Wrap the foil up around the bottom edges of the springform pan to help prevent water from getting in.
In the bowl of a stand mixer fitted with the paddle attachment, beat the cream cheese lowest speed you can until it is smooth. Add in the sugar. Beat in eggs one at a time, allowing each to fully incorporate before adding another.
Fold in vanilla, lemon juice, cornstarch, salt and sour cream and until combined.
Pour in the cheesecake filling into the cooled and prepared springform pan and use a rubber spatula to smooth out the top. Set inside of a baking dish and surround the pan with 1-2 inches of hot tap water. Place into the oven and bake for 55 - 60 minutes, or until the outside edges are firm but the center still slightly jiggles like jell-o.
Turn off the oven, crack the oven door and allow to cool in the oven for one hour.
Remove the cheesecake from the oven and water bath. Gently run a thin knife around the edges to release the cheesecake from the springform pan's ring, and then transfer to a wire rack to cool completely. Chill in the refrigerator for at least 4 hours before the next step.
Just before serving, remove the cheesecake from the springform pan mold and use a small knife or offset spatula to top it with the chilled lemon curd. The cheesecake will stay good uncovered and refrigerated for up to 5 days.
If the egg mixture for the curd splashes onto the side of the bowl it can cook to the side. If this happens, DO NOT scrape it back into your egg mixture, just leave it there.
You can make a graham cracker crust super thick if you like, or build it up the sides of the springform pan using the measuring cup. Either works, it’s personal preference.
Use a nonstick whisk if you have one because a metal whisk can react with the eggs and make them turn gray.