Preheat the oven to 325 degrees and grease a 9 inch springform pan. You will need a large roasting pan that’s bigger and longer than the springform pan. (I use the aluminum foil disposable ones). If you are not sure about your springform holding up in water, you can wrap the outside of the springform pan in heavy duty aluminum foil from bottom up to the sides.)
Using a food processor or a blender, pulse 1.5 cups of pecan halves (or crushed pecans) until it turns to crumbs. Set it aside for crust and frosting.
In a small bowl, combine graham cracker crumbs, cinnamon, and pecan crumbles, mix very well. Add melted butter and mix until all evenly incorporated.
Spread crumb mixture in the bottom of the springform pan, evenly, and press it over the bottom and a little up the sides.
Drizzle caramel topping over the crust.
In a bowl of an electric mixer, beat cream cheese on medium-high speed until smooth and fluffy. Scrape sides and bottom on the bowl and beat for another minute.
Add eggs, one at the time, beating after each addition.
Add pumpkin puree, vanilla, sugar, and sour cream, beat until incorporated. Scrape sides and bottom on the bowl.
Lower speed and add cinnamon and corn starch. Make sure that all ingredients are well combined. Scrape sides and bottom on the bowl and beat for a few more seconds, until all smooth.
Pour half of the cheesecake batter into the pan with crust, over the caramel. Drizzle some more caramel over the cheesecake batter. Pour in remaining cheesecake batter evenly over the top. Make sure the batter is spread evenly in the pan.
Set the pan inside a bigger roasting pan. Carefully pour water into the roasting pan, enough to cover cheesecake about half way up the springform.Carefully place the roasting pan in the oven.
Bake for 70-75 minutes. Turn off the oven and open the oven door half way. Let cheesecake rest for about 10 minutes and take it out of the oven (out of the roasting pan and carefully take off the foil).
Let it rest for 15 minutes on the counter and then gently run a greased butter knife between sides of the cheesecakes and the springform to carefully separate it. (You don't actually have to take the cheesecake out of the pan until ready to serve.)
Cool cheesecake for an hour and then place in the refrigerator. Refrigerate for about 4 hours before adding the frosting.
You will need a paddle and the whisk attachments for the stand up mixer.
First, beat softened butter with paddle attachment in an electric mixer, on medium-high speed, for a couple of minutes. Scrape sides and bottom of the bowl, add heavy cream, and beat for another couple more minutes until light and fluffy.
Switch to whisk attachment, set speed to low, and pour in powdered sugar, pecan crumbles, and cinnamon. Beat on low until sugar is incorporated and raise the speed to medium-high. Beat for 3-4 more minutes.
Spread a thin layer of frosting over the top of the cold cheesecake. Transfer most of frosting into a piping bag and decorate the cheesecake around the edges, leaving some room in the center for the nuts.
Spread pecan in the center and drizzle caramel topping over the top of the cheesecake