Crust
Preheat oven to 350°F (177°C).
In a large mixing bowl, combine graham cracker crumbs, sugar, and melted butter.
Press into the bottom of a 9 x 13 inch baking dish sprayed with nonstick cooking spray; set aside.
Filling
In another mixing bowl, beat together cream cheese, sugar, and vanilla until smooth.
Beat in eggs, one at a time.
Add sour cream and mix again until smooth.
Pour cream cheese mixture over prepared crust, smooth top and bake for 50 minutes.
Turn off the oven, open the door, and let the cheesecake sit in the warm oven for 15 minutes.
Remove from the oven and let cool for an hour.
Caramel Topping
Combine brown sugar and butter in a saucepan over medium heat.
Stir continuously until the butter is melted and sugar is dissolved.
Whisk in condensed milk, corn syrup, and vanilla, and bring to a boil, stirring continuously.
Place a candy thermometer in the caramel mixture and continue to boil until the caramel reaches 225°F (107°C) or reaches soft ball stage.
Let caramel cool in the pan for 3-5 minutes, then pour over cheesecake.
Smooth and let set until cool.
Cut into squares and serve.