Spray or grease an oven dish 9x5 inch (loaf shape).
Peel and prepare the bananas by pureeing them with the help of a fork. Set aside.
In a freestanding mixer whizz the oil and the sugar adding the eggs one by one, the vanilla and the buttermilk. I sometimes just add rum only for a really nice and different flavour. Vanilla is also nice if you fancy adding! Mix for 2 minutes at medium speed.
In a larger bowl, sieve the flour. Add the cinnamon, nutmeg, freshly grated ginger, oat bran and the salt. Make a little well, add the baking powder and the soda bicarbonate followed by the vinegar or the lemon juice.
Add the flour mix to the sugar, oil/butter and egg mixture. Do this by adding little by little and reduce the speed to very low so the flour will not get all puffed out of the bowl, but also we need the flour to get folded in gently until it all incorporates nicely without overmixing.
Once the flour has been incorporated, add the chopped and toasted walnuts as well as the pureed/mashed bananas. Mix until homogenised and split the mixture into two parts. Remove approximately half of the cake batter and place into another bowl.
Add 1 or 2 tablespoon cacao to one part of the mixture and incorporate well. Optionally, add 2 tablespoon coconut flakes into this too if you wish.
Pour the white half of the batter into the greased tin and then pour the cacao one over. You may do the other way around too, it doesn't really matter which one is first added to the tin.
Place in the middle part of the oven and bake at 190C /375F for about 50 minutes. Keep an eye on it towards the end as it all depends on the oven to make sure it doesn't burn. It will be best to test with a toothpick and if this comes out clean, it is ready.
Mix the honey with ½ teaspoon cinnamon powder and brush over the loaf immediately as you have removed it from the oven while this is still hot.
Allow to cool completely before taking out of the tin and slicing it.
Notes
If you're a fan of banana desserts, this is the perfect recipe for you...Enjoy, Enjoy, Enjoy!!