Preheat your oven to 350F and prepare your baking pan by lining with parchment paper. The pan I used measures 8.5 x 4.4 inches. Use butterfly clips to hold parchment paper in place if desired.
In a small bowl, combine your non-dairy milk and ACV and allow to sit for about 2 minutes or until thickened.
In a large bowl, whisk together wet ingredients (maple syrup, applesauce, nut butter, vanilla) and ground flax.
Sift in your remaining ingredients (except for grated apples) and mix until combined. Lastly, fold in your grated apple pieces.
Transfer mixture into lined baking pan and pop into the oven for about 50 minutes (you may need to bake for additional 5-10 minutes if mixture looks undercooked.
In a small bowl, combine all topping ingredients until it forms a crumbly texture. Use your hands to mix.
At the 40 minute mark, layer the topping mixture on top of the apple loaf and return to oven to bake until complete.
Using a chopstick or toothpick, test to see whether the center of the loaf is cooked through. Once completely cooked, allow the loaf to cool for 15 minutes before enjoying or slicing.