Before you start-- put raisins into rum, take butter out of the fridge so it may be soft enough, and sift flour and baking powder. Heat bananas in microwave and cool them down with iced water when not ripe. Preheat the oven at 180C.
Whip butter until it becomes smooth. You can start with your auto hand mixer to save your time.
Add eggs into the whipped butter little by little so they will not separate. Still use the hand mixer until you put in all the eggs.
Put rum raisin and yogurt into step 3. You can now use a wooden or rubber spatula to mix these. Here again be careful they won't separate.
Add the sifted flour and baking powder. You should add 1/3 of the powder, and then again another 1/3, and lastly the rest. Do NOT mix, but FOLD when you put them together.
Put the dough into a buttered and powdered mold. I used a 22cm kouglof mold.
Bake it in an oven at 180C for 40min. Cool it down on a cake cooler.
