01 - Preheat the oven to 350°F. Lightly grease a 2-quart baking dish with butter or cooking spray.
02 - In a large bowl, combine the peach slices, granulated sugar, flour, cinnamon, nutmeg, lemon juice, and salt. Toss thoroughly until the peaches are evenly coated. Transfer the mixture to the prepared baking dish.
03 - In a separate bowl, whisk together the flour, oats, brown sugar, cinnamon, and salt. Add the cold, cubed butter. Using your fingers or a pastry cutter, blend the mixture until it forms coarse, pea-sized crumbs.
04 - Evenly distribute the crumble topping over the peaches, creating a uniform layer.
05 - Bake for 35 minutes, or until the topping is golden brown and the fruit filling is bubbling around the edges.
06 - Allow the crumble to rest for at least 10 minutes before serving. Serve warm with vanilla ice cream or whipped cream if desired.