Preheat oven to 350 degrees F.  oil 2 8- or 9-inch cake pans, line the bottom with parchment.

In a large bowl, mash the bananas until very few lumps remain.  Whisk in the eggs, oil, and vanilla until well combined.  Stir in the baking soda and powder and the almond, tapioca, and coconut flours.

Divide the batter evenly between the pans and bake 30-40 minutes until golden brown and a toothpick inserted in the center comes out clean or with a few moist crumbs.  Cool completely in the pan before carefully removing for assembly.

When ready to assemble the cake, place one banana cake on a platter or cake stand.  Top with 1-2 cups of the cherry jam, depending on how thick you want the layer.  Place the other cake on top.

Make the frosting.  Place chips, and 2 tablespoons milk in a microwave safe bowl.  Microwave in 30 second increments, stirring in between, until melted and smooth.  Stir in additional milk if the mixture is too thick.  Stir in vanilla and spread on top the cake, letting it drip over the edges.

Before the frosting sets, sprinkle with chopped hazelnuts wherever desired.

Serve immediately or store covered at room temperature for up to 3 days.