Step 1: Make the Lemon Curd First

1. In a large mixing bowl, whisk together 2 eggs, 4 egg yolks, and 1 cup sugar vigorously for 4-5 minutes until the mixture becomes thick and pale.
2. Strain ⅔ cup fresh lemon juice to remove seeds and pulp, then add to the egg mixture.
3. In a small bowl, mix 1 tbsp cornstarch with 2 tbsp water to create a slurry, then add this to the mixing bowl.
4. Pour everything into a medium saucepan and cook over medium heat, stirring constantly with a rubber spatula.
5. Cook for 4-6 minutes until the curd thickens and holds its shape on the back of a spoon. If clumps form, use a whisk to break them apart.
6. Remove from heat once thickened, cover with plastic wrap (directly touching the surface to prevent skin formation), and set aside to cool.

Step 2: Prepare the Crust

1. Preheat your oven to 350°F (177°C).
2. Double-wrap the bottom and sides of an 8-inch springform pan with aluminum foil to prevent water from seeping in during baking.
3. Place approximately 15-20 lemon shortbread cookies in a food processor and pulse until you have fine crumbs (about 1½ cups).
4. Add ⅓ cup melted butter to the crumbs and pulse again until well coated.
5. Transfer the mixture to your prepared pan and press firmly into an even layer using a potato masher or large spoon.
6. Bake the crust for 10 minutes, then remove from oven and allow to cool.
7. Reduce oven temperature to 320°F (160°C).

Step 3: Make the Cheesecake Filling

1. In a stand mixer bowl, place 32 oz softened cream cheese and mix on medium-high speed for 7-9 minutes, scraping down the sides often, until light and fluffy.
2. Add 1 cup sour cream (or heavy cream), 1 cup sugar, and 1 tsp vanilla extract. Mix for a few minutes until well combined.
3. Add 4 eggs one at a time, mixing well after each addition and scraping down the bowl frequently for a smooth batter.
4. Zest 2 large lemons directly into the batter and mix until incorporated.

Step 4: Assemble and Bake

1. Pour half of the cheesecake batter over the cooled crust.
2. Add generous dollops of the cooled lemon curd on top and use a knife or spoon to create swirls.
3. Pour the remaining cheesecake batter over this layer.
4. Add more dollops of lemon curd on top and swirl again.
5. Place the springform pan in a deep baking dish or roasting pan and create a water bath by pouring in enough water to reach about 1 inch up the sides of the springform pan.
6. Bake at 320°F for 1 hour and 30-45 minutes, until the center is almost set but still slightly wobbly.
7. Turn the oven off and allow the cheesecake to cool in the oven with the door cracked open for about an hour.
8. Cool at room temperature for another hour, then refrigerate overnight.

Make the Meringue Topping

1. The next day, prepare your Italian meringue topping. Make sure your mixing bowl and whisk are completely clean and grease-free (I wash mine with degreasing soap and vinegar).
2. Place 4 egg whites into the mixer bowl and whisk on high speed for about 2 minutes, just until soft peaks form.
3. In a small saucepan, combine 1 cup sugar and ⅓ cup water without stirring.
4. Attach a candy thermometer and cook the sugar mixture over medium heat until it reaches 238°F (soft ball stage), about 7-8 minutes.
5. With the mixer running on medium speed, slowly pour the hot sugar syrup down the side of the bowl, avoiding the whisk.
6. Once all the syrup is added, increase the mixer speed to high and whisk for 5 minutes until the meringue is voluminous with stiff, glossy peaks.
7. Add 1 tsp vanilla extract and whisk for another 30 seconds.