Preheat oven to 350 degrees F. Grease or line an 8 inch cake pan.
Prepare the crumb topping by adding the flour, sugar, and cinnamon to a small bowl. Stir until combined. Add the melted coconut oil and stir until combined. Set aside while you prepare the cake.
In a large bowl, add the flour, 1 tsp of cinnamon, baking powder, baking soda, and salt. Whisk until well combined.
In a medium bowl, add the brown sugar, maple syrup, coconut oil, applesauce, milk, vanilla, and apple cider vinegar. Whisk until well combined.
Add the wet to the dry. Stir with a spatula until just combined. Don’t overmix! Pour batter into the prepared pan.
Add apples to the medium bowl that had your wet ingredients in. Toss with 1 tsp of cinnamon. Add the apples on top of the cake batter.
Sprinkle the crumb topping evenly over the apples. Bake for 30-35 minutes, or until toothpick comes out clean. Let it cool for 30 minutes before serving!
Before serving, make the glaze by combining the powdered sugar, milk, and cinnamon. Stir until smooth. Add more powdered sugar if you want a thicker glaze or more milk if you want it thinner. Drizzle on top of the cake. Slice and enjoy!