Preheat oven to 350° (177 °c) and grease a 9 x inch (23 x 23 cm) square cake pan
Make the flax egg and let it sit while you prepare the dry and wet ingredients.
In a large mixing bowl, whisk the dry ingredients until fully combined.
Whisk the almond milk, vanilla, maple syrup, and lemon juice together until fully combined.
Pour the wet ingredients and the flax egg into the dry and stir until just combined. Add the apple slices and stir until they’re fully coated. Pour into the cake pan and make sure it’s spread out evenly in the pan.
In a medium bowl, combine the crumble topping ingredients. It will look more like a paste than crumbly. Evenly drop it by the spoonful over the top. Bake for 55 to 60 minutes or until a wooden toothpick inserted in the center comes out clean.
Store in an airtight container in the refrigerator for up to 5 days.
Freeze in a freezer safe container for up to 2 months. Thaw in the refrigerator.
Serving: 45g | Calories: 295kcal | Carbohydrates: 46g | Protein: 5g | Fat: 11g | Saturated Fat: 2g | Polyunsaturated Fat: 4g | Monounsaturated Fat: 5g | Trans Fat: 1g | Sodium: 236mg | Potassium: 219mg | Fiber: 3g | Sugar: 17g | Vitamin A: 19IU | Vitamin C: 2mg | Calcium: 67mg | Iron: 1mg