Peel the apples. Then, cut them into small, even-sized pieces. After that, place the chopped apples in a large bowl.
Add the lemon zest, lemon juice, vanilla extract, salt, sweetener, nutmeg, cinnamon, and cornstarch to the bowl with the apples. Then, thoroughly mix to ensure the apples are evenly coated.
Lightly spray a 9x12 baking dish with oil so the apples don’t stick. Pour the coated apples into the baking dish.
In a separate bowl, mix the rolled oats, flour, sweetener, cinnamon, and salt. Then, add the applesauce and melted butter to the bowl and mix the topping.
Evenly distribute the oat topping over the apple mixture in the baking dish.
Bake this apple crisp at 350°F for 45-55 minutes or until the apples are cooked through and the topping is golden brown and crispy. Once done, let it slightly cool and enjoy!