Preheat oven to 325 degrees F. Line an 8x8" pan with foil, extending the sides of the foil over the edges of the pan. Mist the foil lightly with cooking spray and set aside.
In a large bowl, combine the graham cracker crumbs, brown sugar and melted butter and stir until moistened. Pour into the prepared pan and press into a compact, even layer. Bake for approx. 12 minutes.
While crust bakes, prepare your filling. In the bowl of a stand mixer, cream together the cream cheese and sugar for about 2 minutes or until fluffy and light. Add in the eggs, one at a time, until combined. Lastly, add in the vanilla, sour cream, and two Tablespoons of the dulce de leche sauce.
Pour the filling over the crust and return to the oven to bake for approx. 35-40 minutes or until the center appears just about set and isn't super jiggly. Tent with foil if the top begins to brown too fast. Cool completely, then spread with the remaining dulce de leche in an even layer. Sprinkle with sea salt and refrigerate for at least 4 hours or overnight before serving.