Preheat oven to 400° Fahrenheit and line a 8x8 inch dish with parchment paper.
In a large mixing bowl, combine cassava flour, baking powder and sea salt with a fork.
Using the fork, "cut" coconut butter and oil into dry ingredients until small bits form.
Add coconut milk, maple syrup, apple sauce and apple cider vinegar and mix with fork until combined.
Transfer cake mixture into prepared baking dish and spread out with your hands into an even layer.
Make the topping by combining all the topping ingredients in the bowl you just used and mix until clumps form. Don't overmix - you want it crumbly.
Sprinkle topping over cake, and transfer to the oven. Bake for about 20 minutes. When a knife comes out clean, remove from the oven and let cool before slicing.
Serve and enjoy. You can drizzle some extra coconut butter if you want, too! We love it best served a little warm, so we usually re-heat it for about 10-12 seconds in the microwave.