Grease a bundt pan well with olive oil. In a food processor or with an immersion blender, puree the bananas until very smooth.
Place banana puree in a large bowl and whisk in the olive oil, coconut sugar, eggs, egg yolks, and vanilla extract. In a medium bowl, whisk together the flours, baking powder, baking soda, ground ginger, and sea salt. Add the dry ingredients to the wet and whisk very well to combine.
Pour batter into the prepared pan and heat the oven to 350° F. Let the batter rest while the oven heats to allow the flours to hydrate. Place pan in the oven and bake for 45-50 minutes, until a toothpick inserted in the center comes out clean. Remove pan from oven, place on a rack, and let cool in the pan for 10 minutes before gently turning out onto the rack to cool fully.
Make Glaze
While the cake is cooling, make the glaze: in a small pot over medium heat, combine the almond flour, coconut oil, maple syrup, and sea salt. Melt the ingredients together until smooth, then whisk in the arrowroot powder. When the cake is cool, pour the glaze over the cake.
Cake will keep, well wrapped in the fridge, for 5 days.