Preheat oven to 350 degrees F. Lightly grease the bottom of a 9" round springform pan. Place a parchment round in the bottom of the pan, then liberally grease the parchment round and the sides of the pan with cooking spray. Set aside.
First, make your crumb: in a medium bowl, stir together the brown sugar, flour, cinnamon, melted butter, and chopped pecans. Mixture will come together and be somewhat clumpy. Set aside.
To make your cake batter: In the bowl of a stand mixer, cream together the butter and sugar until soft and pale, about 1 minute. Add in the eggs, one at a time, beating well after each addition, followed by the vanilla extract and bourbon. Add in the sour cream, baking powder, baking soda, salt, and nutmeg, then gradually add in the flour until a soft batter comes together. Stir in the chopped peaches. Pour the batter into the prepared pan and smooth out the top. Drop heaping handfuls of crumbs evenly over the cake. There is a LOT of crumb mixture, but use it all!
Place the springform pan on a baking sheet to catch drips, and bake for approx. 50-60 minutes or until a toothpick or cake tester inserted in the center comes out clean or with moist, not wet, crumbs. Cool completely.
While the cake bakes and/or cools, make your bourbon caramel. In a medium saucepan (make sure your saucepan is bigger than you think you'll need) over medium-high heat, add the granulated sugar, corn syrup and water and stir until sugar is dissolved. Stirring occasionally to prevent burning until the mixture turns deep amber in color. Pay attention* because this happens VERY quickly - within 5-7 minutes - and can go from deep amber to burnt in seconds.
Once the mixture is amber colored, pull from the heat and add in the butter, noting that the butter will cause the mixture to spit and bubble up, so use caution. Whisk in the butter, followed by the heavy cream and bourbon, which will cause the mixture to also bubble violently. Bring the caramel back onto medium heat and cook until boiling, about 1-2 minutes, whisking constantly.
Let the bourbon caramel cool in a mason jar or pourable container until ready to use. Store leftover caramel in the fridge, sealed, up to 2 weeks.