First, make the masa crumbs. Using a food processor, blend the masa flour, almond flour, and brown sugar together, followed by the butter. Pulse until you see crumb-size pieces start to form. Reserve the crumbs in the freezer until ready to use.
To make the bread, start by toasting the masa and cassava flour together in Large Fry. Toast until the flour is well caramelized but not burned; set aside to cool. Using a food processor, mix the ripe plantain and banana together. Process all of the wet ingredients in a food processor until well blended and smooth.
Next, whisk together the cooled toasted flour and remaining dry ingredients Then add the dry ingredients to the wet ingredients in the food processor. Mix until well blended, being sure to scrape the sides of the bowl to even out the batter.
Pour the batter into Breadwinner, alternating between chocolate gems (if using) and batter. Garnish with the optional sliced banana and masa crumbs. Cover the top of Breadwinner with aluminum foil and bake for 35 minutes. Then remove the foil and continue to bake for an additional 15 to 30 minutes.