~ Grease a 13x9 baking dish and set it aside. Preheat the oven to 325.
For crust: Mix the graham cracker crumbs, sugar, melted butter and vanilla. Stir very well, until all incorporated. Press graham cracker mixture into the baking dish, evenly, all over the bottom.
Warm up dulce de leche (take it out of the can and warm it up) so it spreads easily and drizzle it all over the crust. Use a lightly greased rubber spatula to even out dulce de leche.
Cheesecake:
Start beating cream cheese and sugar on medium high speed until smooth, about 2 minutes.
Add vanilla extract and sour cream. Mix until combined.
Add egg and mix until incorporated. Scrape sides and bottom of the bowl and beat until all incorporated.
Add corn starch and while on medium low, pour in heavy cream. Mix until all combined, scrape the sides and bottom of the bowl and mix a little more.
Scoop the cheesecake batter all over the top of the crust and using your hands, gently spread and even it out. Try not to disturb much or mix dulce de leche into the cheesecake mixture.
Mix cinnamon and sugar well and sprinkle it evenly, all over the top of the cheesecake.
Using a butter knife, gently make swirls of cinnamon mixture into the cheesecake, be careful not to dig too deep.
Bake for 40 minutes and then turn off the oven and open the oven door about 1/2 way. Let cheesecake rest for about 5 minutes.
Take out the cheesecake and gently run a greased, thin spatula (or butter knife) along the edges of the cheesecake to gently separate it from the side.
Let it cool to room temperature before cutting or refrigerating.
You can eat it warm but it's best after being refrigerated for at least 4 hours.