Set the oven to 175 degrees. Mash the bananas with a fork and add the cinnamon.
Mix all the dry ingredients in a bowl, melt the butter and mix the milk. Mix everything together and pour into a greased sugar cookie mold.
Bake the cake in the lower part of the oven for about 45-60 minutes. Feel with a knit, it does not have to be completely dry, but it must not be runny. Try it out and then serve with a click of cream or eat it as it is.