Layer 2 large heavy-duty foil and put a 9-inch springform pan in the middle, as pictured. Tightly wrap the pan with foil, being careful not to make a hole.
To make the crust:
Crush graham crackers in a food processor until fine crumbs form. And add sugar and then melted butter and pulse until the crumbs are evenly moistened.
Transfer the crumbs into a 9-inch springform pan. Press the mixture onto the bottom and up the sides of the pan. Refrigerate while working on filling.
Preheat the oven to 350°F (175°C).
To make the filling:
In a mixing bowl with paddle attachment, beat cream cheese on medium speed until fluffy, about 2 minutes.
Stir in sugar, about ¾ of dulce de leche, sour cream, vanilla extract and salt. Beat the mixture until smooth, about 2 minutes, scraping the sides of the bowl halfway.
Add eggs one at a time, mixing well after each addition on medium low speed. Scrape the sides of the bowl again and mix for another 30 seconds.
Pour the batter into the prepared crust. Tap it on the counter couple of times to burst any trapped air bubbles.
To bake:
Place the cheesecake in a large roasting pan and pour 1 cup of hot water into the roasting pan. (Alternatively, place a baking pan of water on the bottom rack, if you don't have a large enough roasting pan to fit the cheesecake pan.)
Bake the cheesecake for 1 hour, or until the edges of the cheesecake is set, but the center is slightly wobbly.
Turn off the oven heat and cool the cheesecake in the oven slowly for 1-2 hours.
Remove from the oven and cool completely. Then cover with a plastic wrap and refrigerate it for at least an hour, or preferably overnight.
When ready to serve, run an offset spatula (or a butter knife) around the edges, and remove springform sides.
Spread the reserved dulce de leche on top and sprinkle flakey sea salt, if desired.
Notes
Note 1: You'll need 2 sleeves of graham crackers, equivalent to 260g of crackers.Note 2: Use full fat, brick-style cream cheese. No whipped or reduced fat cream cheese for the best result.Storing Tips: - This cheesecake is a perfect make-ahead dessert. Store cooled cheesecake, tightly covered, in the fridge for up to 3 days. Or freeze for up to 1 month. - Refrigerate leftover cheesecake, in an airtight container, for up to 5 days.