Preheat & Prep. To start, preheat oven temperature to 350 degrees F. Line a metal 8×8″ baking dish with parchment paper.
Combine Wet Ingredients. In a food processor or blender combine bananas, eggs, syrup, vanilla, and almond extract. Blend until smooth (you want the bananas very smooth for this cake).
Add Dry Ingredients. Scrape down the sides of the food processor and add the dry ingredients--almond flour, arrowroot, baking soda, baking powder, and salt. Pulse until just combined.
Transfer. Scrape down the sides of the food processor again, then pour the batter into your prepared baking dish. Smooth into an even layer.
Bake at 350 degrees F. for 28-30 minutes, or until the cake is golden brown and a toothpick inserted in the center comes out clean with just a few moist crumbs.
Cool Before Frosting. Place cake pan on a wire rack and let the cake cool completely before adding the chocolate ganache. (You can put it in the refrigerator to speed up this process, if desired.)