Peel and slice the apples into then slices.
Transfer the apples to a mixing bowl along with ½ cup of sugar and a tablespoon of fresh lemon juice. Mix well and let the apples sit for approximately 30-45 minutes. This step works its magic, softening the apples and allowing the sugar to dissolve.
Combine the wet ingredients in a separate bowl and the dry ingredients into another bowl.
After the apples have been sitting, toss the apples into the dry ingredients and mix well to coat all the apple slices. Then, gently fold in the wet ingredients until combined. Allow the batter to rest for 20 minutes for the flavors to meld together.
Preheat the oven to 350°F. Prepare your baking dish by giving it a good spray with cooking spray or lining it with parchment paper.
Transfer the batter into the prepared baking dish. In a small bowl, mix together the ingredients for the cinnamon crumble topping and spread it over the batter.
Place the baking dish into the preheated oven. Bake for 45-50 minutes if using a 9x9 dish, or 35-45 minutes for a 9x13, or until a knife inserted in the center comes out clean.
After baking, let the cake rest in the baking dish for 30 minutes. Then, transfer the cake to a wire rack to cool completely. Enjoy the delightful aroma wafting through your kitchen. Slice and Enjoy!