Cream 125 g butter and sugar with a food processor or with the whisk of the hand mixer until the mixture is light and airy. Add the eggs and continue beating for about 1 minute
Peel the bananas and mash them with a fork. Stir in banana puree with a wooden spoon or dough scraper. Chop the nuts. Briefly stir in flour, baking soda, baking powder and salt until just enough to form a dough. Stir in spices, nuts, coconut, raisins and ginger
Grease a square 12-cup tartlet mould or the troughs of a muffin tray (12 troughs). Pour in the dough (approx. half full) and bake in a preheated oven (electric cooker: 200 °C/ convection oven: 175 °C/ gas: see manufacturer) for 15-17 minutes (stick test!). Let the cake rest for about 10 minutes, then let it cool down on a cake rack
For the Frosting, whisk 125 g butter and cream cheese smooth with the whisks of the hand mixer. Sift icing sugar. Gradually add lemon zest and icing sugar to the cream cheese and stir at highest speed until the Frosting is light and airy. Spread on the cakes with a pallet or knife. If necessary, pour some caramel sauce on the cakes and decorate with walnut halves
Waiting time approx. 1 hour