**Preheat Oven:** Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish.
**Prepare the Apples:** In a large mixing bowl, toss the sliced apples with granulated sugar, brown sugar, flour, cinnamon, nutmeg, salt, vanilla extract, and lemon juice until evenly coated. Spread the mixture evenly into the prepared baking dish.
**Make the Crumb Topping:** In another bowl, mix the flour, oats, brown sugar, cinnamon, and salt. Pour in the melted butter and stir until the mixture forms a crumbly texture.
**Assemble:** Sprinkle the crumb topping evenly over the apple mixture.
**Bake:** Bake in the preheated oven for 40-45 minutes, or until the topping is golden brown and the apples are bubbling.
**Cool and Serve:** Allow the crisp to cool slightly before serving. Enjoy warm with vanilla ice cream or whipped