Preheat oven to 350°F and generously spray a 9-inch springform pan with baking spray.
Pulse graham crackers or gingersnaps until fine, then mix with melted butter and sugar.
Press crust mixture onto bottom and two-thirds up the sides of the springform pan.
Place pan on a lined baking sheet and bake crust for 10 minutes until golden; cool.
Reduce oven temperature to 325°F and wrap the springform pan in three layers of aluminum foil.
Make caramel by melting sugar evenly over medium-low heat without stirring; gently shake pan to melt all sugar.
Remove pan briefly from heat to add bourbon; return to heat and cook 2 minutes to burn off alcohol.
Stir in butter, salt, then chopped apples, cooking until apples are soft and caramel coats them.
Remove from heat and stir in cinnamon and vanilla; press apple mixture evenly into crust.
Beat cream cheese, sugar, and cornstarch on low speed until smooth, scraping bowl as needed.
Add eggs one at a time on low speed, incorporating fully before each addition.
Mix in egg yolk, sour cream, and vanilla extract; pour batter over caramel apple layer in pan.
Place wrapped springform pan in a roasting pan and add 2 inches of boiling water around it.
Bake for 1 ½ to 2 hours, until the cheesecake center does not tremble when tapped.
Cool cheesecake at room temperature for 30 to 45 minutes, then refrigerate uncovered overnight.
For praline topping, heat bourbon in a saucepan to burn off alcohol for 2-3 minutes.
Add brown sugar, heavy cream, butter, salt, and vanilla, bring to boil and cook 3 minutes.
Remove from heat, stir in pecans, and allow topping to cool completely.
Run knife around cheesecake edges, release from pan, and transfer to serving plate.
Spoon bourbon praline pecan topping over the cheesecake and serve chilled or room temperature with whipped cream if desired.