Preheat oven to 350°F (175°C) and grease a 10" springform pan.

Combine melted butter with Oreo cookie crumbs in a bowl until resembling wet sand. Press firmly into the bottom of the prepared pan. Bake for 10 minutes then let cool.

Beat together softened cream cheese, sour cream, and granulated sugar until smooth, about 2-3 minutes. Mix in cornstarch and vanilla until combined.

Add egg yolks one at a time, mixing briefly after each to avoid over-whipping.

Pour filling into the cooled crust and spread evenly. Wrap the bottom of the pan in foil and place in a roasting pan. Fill the roasting pan with hot water halfway up the sides.

Bake at 325°F (160°C) for 1.5 hours without opening the oven door.

Turn off the oven, leaving the cheesecake inside for another 30 minutes.

Remove from oven and let cool on the counter for 30 minutes, then refrigerate for at least 4 hours or overnight.

To make the caramel sauce, heat water and sugar in a saucepan until dissolved. Add butter and simmer until amber. Remove from heat and whisk in cream and sea salt.

Serve cheesecake sliced, drizzling with homemade caramel sauce. Optional: add whipped cream.