- Preheat oven to 350 degrees.
- In a food processor, puree plantain, maple syrup, palm shortening, and vanilla extract until smooth.
- Whisk together grain free baking powder, sea salt, and sweet potato flour in a separate bowl, then add to the food processor and puree until just combined.
- Grease a 6x2 inch round cake pan and cut out a piece of parchment paper to fit into the bottom of the pan.
- Evenly scoop the cake batter into the prepared pan.
- To create the topping, pulse the banana chips, cinnamon, sea salt, and sweet potato flour until crumbly, then add in palm shortening and maple syrup, pulsing until a sticky crumble forms.
- Transfer the crumble to the top of the cake batter and lightly press it down.
- Place the cake in the oven to bake for 40-45 minutes, until the cake has pulled away from the sides and the middle is no longer wet inside when a toothpick is inserted.
Coconut oil can be used in place of the non-hydrogenated palm shortening.