Lightly spray an 8-inch springform pan with baking spray Cut a circle of parchment paper the size of the bottom of the pan and place it in the pan. Using a medium bowl, combine graham cracker crumbs and pretzel crumbs. Add in butter and sugar and mix with a fork until the consistency of wet sand. Add mixture to pan and press firmly into the bottom and about ¾" up the sides of the pan. Place crust in the freezer while preparing apples and filling.
Mix peeled and diced apples with sugar and cinnamon. Set aside. Using a stand or hand mixer, beat the cream cheese in a medium bowl until fluffy. Make sure to scrape the bowl to get all the cream cheese mixture. Add brown sugar and granulated sugar and mix for approximately 2 min.
Add apple juice, vanilla, and cinnamon and mix until thoroughly combined. Add in eggs, one at a time, mixing each on low until just combined. Add in sour cream and mix on low until combined and batter is smooth. Gently fold in prepared apples.
Pour filling into prepared pan and cover the pan with foil, sealing edges. Add 1½ c. of water to the bottom of Instant Pot. Place the cheesecake pan on trivet or sling and lower into pot. Seal pot according to your instructions. Cook on high pressure for 35 min, allow to sit for 10 min, then manually release.
The Cheesecake should jiggle a bit in the middle. If too loose, cook for an additional 5 min. Place on a wire rack, in a pan to cool for at least two hours or until you notice the sides of the pan pulling away from the cheesecake. Run a knife around pan edges and remove cheesecake from pan.
Place caramels and water in pan and heat over low temperature on stovetop, stirring constantly until smooth and melted. (Can do in the microwave in short increments until melted if you like.) Allow to cool until thickened a bit. It should be a pouring consistency but not too liquid. If too thick, add a little of the cream to thin.
Pour caramel over the top of the cheesecake and allow to drip down the sides. Sprinkle flaked salt across the top evenly. Place pecan halves or chopped pecans over top of caramel if you choose.