Preheat the oven to 350°F (175°C).

In a mixing bowl, combine sliced peaches, granulated sugar, lemon juice, cornstarch, and cinnamon. Toss until well mixed.

Pour the peach mixture into a greased baking dish.

In another bowl, mix together flour, brown sugar, rolled oats, melted butter, and salt until crumbly.

Spread the crumble topping evenly over the peach filling.

Bake in the preheated oven for 30 minutes or until the topping is golden brown and the peaches are bubbly.

Remove from the oven and let cool slightly before serving.