1. Preheat oven to 180 ° and peel the bananas. Cut into cubes and chop the walnuts and melt the butter.
2. Whisk the melted butter with the sugar until the mixture whitens. Incorporate the eggs one at a time as well as the flour and yeast.
3. Pour the crushed walnuts and diced bananas. Butter and flour a mould and pour the preparation.
4. Bake the cake for 45 minutes.