Preheat your oven to 325°F (160°C) and line a 9-inch springform pan with parchment paper.

Combine graham cracker crumbs, granulated sugar, and melted butter. Press into the bottom of the pan and bake for 10 minutes. Let cool.

Beat softened cream cheese until smooth. Gradually add sugar, then eggs one at a time. Mix in vanilla extract, sour cream, and heavy cream until well combined.

Pour the cheesecake filling onto the cooled crust and evenly spread. Tap to remove air bubbles.

In a saucepan, combine peach slices, sugar, cornstarch, cinnamon, nutmeg, and lemon juice. Cook until bubbly for about 5-7 minutes. Cool slightly.

In a bowl, whisk flour, brown sugar, oats, and cinnamon. Cut in cold butter until crumbly.

Spoon the peach mixture over the cheesecake filling, spreading evenly. Sprinkle the crumble topping over the peaches.

Bake for 1 hour. Leave in the oven with door ajar for 1 hour to cool.

Cool to room temperature, then refrigerate for at least 4 hours or overnight before serving.