If You have no mini bundt cake mould  You can bake it in a loaf tin as well. Due to banana, the cake will remain soft and tender even after 2 days. 

Ingredients:

 (to 16 db mini bundt cakes or one loaf  tin)

Preheat oven to 180 C.  Mash banana with a fork, add peanut butter, yoghurt, sugar and put in a stand mixer’s bowl. On a medium level mix until well combined. Add the eggs separetely.

In a medium size bowl whisk both type of flour, baking soda and seasoning. Add the flour mixture to banana batter spoon by spoon. Add the oil and stir carefully. Prepare the tin: if You use silicon mini bundt cake brush with oil the  cavity. If You use regular loaf tin, rub with some butter and then dust with flour.
Bake mini bundt cakes  in the oven for 12-15 minutes or the loaf for 30-35 minutes. Probably the top of the cakes will rise up, but when it’s getting to cool it will go back. If not, and disturb You, just use a sharp knife and cut to flat. If You bake in a loaf tin, it could happen, too. But You can just cover with cinnamon or any other type of frosting.  

For the frosting put sugar and cinnamon into  a tall glass. Add water and mix until smooth. If it’s too thick, just add some more water to spread it preciously. Cover  the top of cake all over with a teaspoon. 

Just a note: I covered the half of the cakes with frosting, so if You want to cover all of them, just double the size of the amounted listed above. 

Original recipe comes from Cookin Canuck blog, here  You can read it.