Preheat oven to 350°F (175°C). Grease a 9"x 13"x 2" baking pan. If you like, you can line the pan with parchment paper and grease the lining.
Mix the graham cracker crumbs, sugar, and cinnamon. Add the melted butter. Stir until combined.
Press the crust mixture firmly onto the bottom of the prepared pan. Bake 10 minutes. Cool on a wire rack.
To make the filling:
Using an electric mixer on medium speed, beat the cream cheese and sugar until smooth and creamy. Add the eggs, one at a time, mixing well after each addition. Mix in the dulce de leche and vanilla.
Spread the batter evenly over the partially baked, cooled crust. Bake 38-42 minutes, or until the center is set and the edges are puffed and slightly cracked. Cool completely on a wire rack.
To make the glaze:
Place the dulce de leche and cream in a microwave-safe bowl. Heat in 10-second intervals until melted. Stir until blended. If the mixture is too thick to pour, add more cream, a teaspoonful at a time, until pourable.
Pour the glaze over the cooled cheesecake. Spread evenly. Refrigerate 1 hour or until chilled. (Note that the glaze will not become firm.)
Cut into bars. Sprinkle with sea salt, if using.
Notes
Dulce de leche can be found in most supermarkets. Look near the condensed milk or in the specialty foods section. I used most of a 15.85 ounce jar.