Preheat oven to 350° and line an 8×8 pan with parchment paper. Set aside.
For crumb topping:
In a medium bowl, whisk to combine ¼ cup almond flour, ¼ cup coconut sugar and pinch of cinnamon. Use a pastry cutter to cut in the coconut oil until completely combined and crumbly. Set aside.
For cake:
In another medium bowl, whisk together 2 ¾ cups almond flour, ¼ cup coconut flour, baking powder, baking soda, cinnamon, and salt.
In a large bowl, whisk together coconut oil and coconut sugar until well combined.
Add eggs, cider, almond milk and vanilla extract and use a wooden spoon to combine.
Add dry mixture to wet mixture until combined.
Press batter into prepared pan. Top with crumb mixture, chopped apples, and walnuts.
Bake for 40-45 minutes, or until toothpick inserted in the center comes out clean.
Let cool completely in pan. Cut into 9 pieces and enjoy!
Notes
Store in an airtight container in the fridge for up to 2 days (it's best the same way or next).