Preheat oven to 350 degrees Fahrenheit. Grease a nine-inch springform or square pan.

Toss apples with coconut sugar, cinnamon, and lemon juice. Set aside.

Make crumb: Mix flour, coconut sugar, cinnamon, and salt. Add avocado oil and mix until crumbs form.

In a bowl, whisk flour, baking powder, baking soda, salt, and cinnamon.

In another bowl, whisk eggs, coconut sugar, honey, and oil. Mix in sourdough discard, applesauce, milk, and vanilla.

Add dry ingredients to wet and mix just until combined.

Spread half the batter into the pan. Top with half the apples and crumbs. Add remaining batter, then remaining apples and crumbs.

Bake 50–60 minutes, until a toothpick comes out clean or with a few moist crumbs. Cover loosely with foil if the top browns too quickly.

Cool in pan for around 20 minutes, then remove and cool completely.