Preheat your oven to 450°F.

Separate the egg yolk from the whites and set the yolk aside.

Split the vanilla beans and scrape out the seeds.

In a large bowl, mix the cream cheese and mascarpone together, whipping on high until the mixture is light and fluffy.

Gradually add the sugar in quarters, ensuring to whip until fully combined after each addition.

Stir in the fine sea salt.

Add the whole eggs one at a time, beating well after each addition.

Incorporate the reserved egg yolk into the mixture.

Add the vanilla bean seeds (or vanilla paste/extract) and blend well.

Slowly pour in the heavy cream while continuing to beat the mixture.

Sift in the cornstarch and gently fold it in until fully hydrated.

Line a 9-inch springform pan with parchment paper, trimming any excess and creating a border with an additional piece of parchment.

If desired, strain the batter through a fine-mesh sieve to eliminate lumps.

Tap the pan to release any air bubbles and smooth the surface.

Bake in the preheated oven at 450°F for 12 minutes, then rotate the pan 180° and bake for another 12 minutes.

Lower the oven temperature to 325°F and continue baking for 20-25 minutes, or until the internal temperature reaches 140°F.

Once done, remove the cheesecake from the oven; the center should still be jiggly.

Allow it to cool to room temperature, then refrigerate for at least 4 hours or overnight.

Before serving, let the cheesecake sit at room temperature for a short while, then slice and enjoy.