Preheat oven to 350°F. Line the bottom of a 9-inch springform pan with a piece of parchment paper, then line the sides with a long piece of parchment paper. Set aside.
To make the crust, mix the graham crackers, sugar, and brown sugar in a medium-sized bowl. Add the melted butter and stir until the mixture resembles wet sand. Press the crust mixture into the bottom and sides of the springform pan. The crust will be very thick. Place the springform pan into the fridge to chill for 20 minutes while you make the cheesecake batter.
4½ cups crushed graham crackers, ¼ cup granulated sugar, ¼ cup brown sugar, 1 cup unsalted butter
For the base cheesecake batter, place the cream cheese and sugar into the bowl of a stand mixer fitted with a paddle attachment. Beat together on high speed for 2 minutes to ensure that it is smooth and creamy. Use a rubber spatula to scrape the sides of the bowl down. Add in the heavy cream, lime juice, vanilla, and salt and beat together until combined. Add in the eggs and beat together for 15 seconds. Lastly, add in the cornstarch and beat together to incorporate.
24 ounces cream cheese, ⅓ cup granulated sugar, ⅓ cup heavy cream, 2½ teaspoons lime juice, 1 teaspoon pure vanilla extract, 1 teaspoon kosher salt, 3 large eggs, 1½ tablespoons cornstarch
Divide the cheesecake batter into 2 medium-sized bowls.
For the caramel layer, mix half of the cheesecake batter and the caramel together until combined. For the chocolate layer, mix half of the cheesecake batter and the melted chocolate together until combined.
½ cheesecake batter (see above), ⅓ cup caramel sauce, ½ cheesecake batter (see above), ⅓ cup chocolate chips
Take the crust out of the refrigerator and pour the caramel cheesecake batter into it in a smooth layer. Wrap the bottom and sides of the springform pan with tin foil to prevent any water from seeping in. Place the springform pan into a large baking pan or broiler pan. Fill the broiler pan with 1 inch of warm water to create a water bath. Place the pans into the oven to bake for 50 minutes. Once baked, remove from the oven and place on a cooling rack to cool slightly for 5 minutes.
Gently spoon the chocolate cheesecake batter on top of the caramel layer. Gently tap the sides of the pan to get the chocolate layer smooth. Do not smooth out with a spoon or rubber spatula, as this can cause the chocolate batter to go down into the caramel layer. Place the pans back into the oven to bake for 30 minutes.
Once baked, turn the oven off and let the cheesecake rest inside with the door closed for 30 minutes. Prop the oven door open slightly and let the cheesecake rest for another 30 minutes. Once rested, remove from the oven, unwrap the tinfoil and place the springform pan onto a cooling rack to cool completely. Once the cheesecake has cooled, cover and place in the refrigerator to chill for at least 8 hours.
To make the ganache, heat the heavy cream in a microwave safe bowl for 1 minute. Pour the heated heavy cream on top of the chocolate chips. Let stand for 1 minute to allow the chocolate to melt before mixing until smooth.
5 tablespoons heavy cream, ⅔ cup chocolate chips
Once the cheesecake has chilled, uncover and pour the ganache on top. Smooth out. Release the springform and remove the sides from the cheesecake. Slice and serve.