Add the flax eggs, vegan buttermilk, coconut oil, and vanilla extract. And combine well.
Sift the flour into a mixing bowl and add baking powder, baking soda, salt, and mix.
Now mix the dry ingredients with the wet ingredients and whisk until you get an even mix.
Place into the oven and bake for 30-35 minutes or until a toothpick inserted into the center comes out clean. Check it at 30 minutes.
Place the whole sheet pan onto a cooling rack and leave to cool completely before frosting.
Prepare this as a sheet cake and 'wow' and entertain your guests. They will never guess that it is a vegan banana cake.