How to Make It
Prepare the Crust: Preheat oven to 350°F. Coat a 9-inch springform pan with cooking spray. Stir together graham cracker crumbs, melted butter, and sugar in a medium bowl until evenly combined. Transfer to prepared pan, pressing crumbs along bottom and up sides of pan. Bake in preheated oven until set and light golden, about 10 minutes. Let cool on a wire rack 30 minutes (do not turn off oven).
Meanwhile, prepare the Filling: Beat cream cheese and sugar with a heavy-duty stand mixer fitted with a paddle attachment on medium speed until just smooth, about 1 minute. Scrape down sides of bowl using a rubber spatula. Add sour cream and vanilla, beating until just combined and smooth, about 1 minute. Add eggs 1 at a time, beating on low speed until just combined, about 30 seconds. Do not overbeat. Fold in chopped peaches. Set aside until ready to use.
Pour Filling over cooled Crust; gently jiggle pan to level. Place cheesecake in a slow cooker liner; place cheesecake in liner in a roasting pan large enough to fit springform pan with at least 2 inches around all sides. Place roasting pan in oven; carefully pour enough boiling water into roasting pan around cheesecake to fill halfway up sides of springform pan (be careful to not let any water get into slow cooker liner). Bake at 350°F until cheesecake is just set on top, about 35 minutes.
While cheesecake bakes, prepare the Topping: Stir together sliced peaches, brown sugar, butter, lemon juice, cornstarch, and cinnamon in a small saucepan. Cook over medium, stirring occasionally, until mixture thickens, about 5 minutes. Remove from heat; set aside.
Prepare the Crumble: Stir together flour, granulated sugar, and brown sugar in a small bowl. Rub butter into flour mixture using your fingertips until mixture resembles coarse meal.
Open oven door, and slide out rack with cheesecake (without removing from oven). Carefully spoon Topping evenly over cheesecake, and sprinkle with Crumble. Slide rack back in, and close oven. Continue baking at 350°F until cheesecake is golden on top and almost set in center, 30 to 35 minutes. Turn oven off, and prop oven door ajar about 1 inch. Let cheesecake stand in oven 1 hour.
Remove cheesecake from oven; let cool 1 hour. Transfer to refrigerator; chill 8 hours. Slice and serve.