Preheat the oven to 350 degrees. Place bananas on a baking sheet with the skins still on. Place in the oven and bake for 30 minutes. Grease two 8 inch cake pans. Add a square of parchment paper in the middle of the pan and grease the paper.
After the bananas have cooled enough to take them out of their skins, place them in your mixer bowl. Add oil and sugar mixture and whisk on low with whisk attachment
After the mixture is combined, add the eggs and vanilla and scrape down the sides. Give it a quick whisk until everything is incorporated.
In a medium bowl, sift flour, baking soda, salt, and baking powder.
Add the sifted dry mixture into the mixer bowl with the wet. Whisk on low until flour is somewhat incorporated. Turn on medium and whisk until flour is just incorporated.
Bake at 350 for 30 to 35 minutes. Place on cooling rack until cooled.
A moist, banana cake complimented with a German buttercream.