Allow the casserole to cool slightly before serving. Enjoy warm.
Variations & Tips
For a nutty twist, add 1/2 cup of chopped walnuts or pecans to the crumb topping. If you prefer a less sweet version, reduce the amount of granulated sugar to 3/4 cup. You can also experiment with different types of apples for varying levels of sweetness and tartness. For a gluten-free option, substitute the all-purpose flour with almond flour or a gluten-free baking mix.