Preheat the oven to 350°F and wrap the outside of a 9-inch springform pan with two layers of heavy-duty foil. Mix the graham cracker crumbs, chopped pecans, brown sugar and melted butter, press into the bottom of the pan and bake for 10 minutes.
Let it cool, reduce the oven to 325°F and bring a kettle of water to a boil. Blend the cottage cheese in a food processor or blender for 2 to 3 minutes, scraping down the sides, until completely silky with no curds left.
Add the cream cheese, brown sugar, cornstarch, vanilla and salt and blend until smooth. Add the eggs and pulse just until combined, then pour the filling over the crust.
Set the springform in a roasting pan, add hot water about 1 inch up the sides and bake for 60 to 70 minutes, until the edges are set and the center jiggles slightly.
Turn off the oven, crack the door and let the cheesecake cool inside for 1 hour. Remove from the water bath, loosen the edge with a thin spatula, cool to room temperature and refrigerate for at least 8 hours.
Heat the heavy cream until steaming, pour it over the chopped chocolate, let it sit for 3 minutes and stir until smooth. Let it cool and thicken slightly for about 10 minutes.
Release the springform ring and arrange the toasted pecans over the top. Drizzle generously with the caramel sauce and chocolate, then finish with flaky sea salt.