Prepare the Oven: Preheat your oven to 375°F (190°C). Grease a 9-inch baking dish with butter or cooking spray.
MAKE THE PEACH FILLING:
In a mixing bowl, combine peaches, sugar, cornstarch, cinnamon, and nutmeg.
Toss until the peaches are evenly coated.
Spread the peach mixture into the prepared baking dish.
PREPARE THE CRUMB TOPPING:
In another bowl, mix the flour, brown sugar, granulated sugar, and salt.
Add the cold, cubed butter. Use a pastry cutter, fork, or your fingers to blend until the mixture resembles coarse crumbs.
Stir in chopped nuts, if using.
Assemble the Crumble:
SPRINKLE THE CRUMB TOPPING EVENLY OVER THE PEACH FILLING.Bake:
Place the baking dish in the preheated oven.
Bake for 30-35 minutes, or until the topping is golden brown and the filling is bubbling around the edges.
Cool and Serve:
Allow the peach crumble to cool for about 10-15 minutes.
Serve warm with a scoop of vanilla ice cream, whipped cream, or a drizzle of caramel sauce.