This is a delicious cake, but I would recommend that you make this when you have company coming or if you know that it will be eaten within a day or so.
Preheat the oven to 350°F. Lightly butter two 9-inch cake pans and line the bottom of the pans with parchment paper. Butter the parchment then dust pans with flour, tapping out excess flour. Alternatively you can use cooking spray in place of the butter and flour.
Whisk together the flour, baking soda, baking powder, cinnamon, ginger, allspice, and salt in a medium bowl.
In mixer at medium speed, beat the bananas until very smooth. Add in the granulated sugar followed by the agave, honey, oil, vanilla and banana extract. Beat until well combined. Turn mixer down to low and gradually add in dry ingredients. With the mixer set at medium speed, beat until smooth, scraping down the sides of the bowl with a rubber spatula as necessary. Separate batter into prepared pans.
Bake until a toothpick inserted in the center of the cake comes out clean, about 30-35 minutes. Let the cakes cool on a wire cake rack for 20 minutes. Gently loosen the sides of the cakes by running a metal spatula around the inside of the pan. Place the wire rack over each cake and invert. Tap the pan to loosen and remove. Set the cakes right side up and cool completely.
To make the ganache, bring the cream to a simmer. Remove from heat whisk in the malted milk powder. Add the chocolate chips and let sit for a couple of minutes to allow them to melt. Whisk the ganache until smooth and then set transfer to a small bowl. Allow ganache to sit and thicken up, stirring occasionally, until it is thick and spoonable, about an hour. Do not refrigerate.
Place a dab of the ganache into the center of a serving plate. Place the bottom cake layer on the plate. This will help keep the bottom lair from sliding around. Spread about one-third of the ganache over the bottom layer, banking it a little thicker around the perimeter of the cake layer. Thinly slice the ripe banana and divide it around the frosted layer. Top with the second cake layer and press lightly. Pile the remaining ganache in the center of the top layer. Using the back of a spoon, begin spreading the ganache out toward the edges. Allow ganache to topple over the sides. Use the back of the spoon to coax the ganache down the sides and gently spread it around. Add a few sprinkles for fun.