Crust:
Blend cookies in food processor with butter until finely ground. Press crushed Oreo cookies evenly onto bottom of a 9-inch spring form pan.
Cheese cake filling
In a large bowl combine cream cheese, sugar, dark corn syrup, corn starch, vanilla and mix with electric mixer on medium speed until well blended. Add eggs, 1 at a time, beating just until blended after each addition.
Stir in melted chocolate and sour cream.
Pour mixture cheese mixture over prepared crust.
Bake at 350 degrees for roughly 15 minutes. Then lower temperature to 200 degrees and bake for 1 hour and 10 minutes. Turn of the oven
Remove the cheesecake from the oven and run a knife around the inside of the edge of the pan to prevent the cake from sticking to the pan.
Return cheesecake into the oven without turning it on, for an additional hour
Chill for at least 4 hours, or preferably overnight.
Caramel frosting:
Melt butter in a small pan over medium heat. Mix in brown sugar and salt and stir, until the sugar dissolves.
Then, bring to a boil, pour into a medium bowl. Let it cool for about 15 minutes.
Stir in the confectioners' sugar, milk and vanilla. Mix well; if the mixture appears too thin, add more confectioners' sugar to reach desired consistency or add milk if too thick. Spread or pipe over cake