Preheat your oven to 375°F and spray an 8x8 glass or ceramic baking dish with non-stick baking spray.
In a large mixing bowl, toss the apple slices with ¼ cup granulated sugar, 3 tablespoons melted butter, 1 tablespoon cinnamon, and the lemon juice, making sure to coat the slices completely.
Spread the slices in an even layer in the baking dish and set aside.
In a separate large mixing bowl, combine the remaining 1 cup granulated sugar, brown sugar, flour, salt, ½ tablespoon cinnamon, nutmeg, and cubed butter with a hand blender on low or two forks until well combined and smooth loose dough forms. Spread the topping over the apples. The topping will seem very dry at first, keep mixing it, it will soften and combine into a less crumbly texture.
Bake uncovered for 45-50 minutes, until bubbling and the topping is golden brown.
Let sit for 10 minutes to cool slightly.
Serve warm or room temperature with ice cream or whipped cream and caramel topping.