Preheat your oven to 190°C (375°F). Lightly grease an ovenproof dish (approximately 20x20cm or 8x8 inches) and set aside.

**Prepare the Filling:** In a large mixing bowl, combine the peeled, cored, and sliced apples with 2 tablespoons of granulated sugar, ground cinnamon, and lemon juice. Toss gently until the apples are evenly coated. Pour the apple mixture into your prepared ovenproof dish and spread it out evenly.

**Prepare the Crumble Topping:** In a separate medium bowl, combine the all-purpose flour, 75g of granulated sugar, rolled oats, and salt. Add the cold, cubed butter to the dry ingredients. Using your fingertips, rub the butter into the flour mixture until it resembles coarse breadcrumbs or small pebbles. Ensure there are no large lumps of butter remaining.

**Assemble and Bake:** Evenly sprinkle the crumble topping over the apple filling in the dish, ensuring it covers the apples completely.

Bake in the preheated oven for 30-40 minutes, or until the crumble topping is golden brown and the apple filling is tender and bubbling around the edges. If the topping browns too quickly, you can loosely cover it with foil.

Remove the apple crumble from the oven and let it stand for 5-10 minutes before serving. This allows the filling to set slightly. Serve warm with your preferred accompaniment.