Preheat the Oven: Preheat your oven to 350°F (175°C).
Prepare the Peaches: In a large bowl, combine the sliced peaches, 1/2 cup of granulated sugar, lemon juice, and cinnamon. Toss to coat the peaches evenly.
Make the Crisp Topping: In another bowl, mix the flour, oats, brown sugar, melted butter, and salt until crumbly.
Assemble the Dish: Pour the peach mixture into a greased baking dish. Evenly spread the oat topping over the peaches.
Bake: Bake in the preheated oven for 30-35 minutes, or until the topping is golden brown and the peaches are bubbly.
Cool and Serve: Remove from the oven and let cool slightly before serving. Enjoy warm, preferably with ice cream or whipped cream.