Preheat oven to 180 degrees C. Grease and flour two 20cm round cake tins. In a small bowl, whisk together flour, bicarb soda and salt; set aside.
In a large bowl, cream butter, white sugar and brown sugar until light and fluffy. Beat in eggs one at a time. Mix in the bananas. Add flour mixture alternately with the buttermilk to the creamed mixture. Stir in chopped walnuts. Pour batter into the prepared cake tins.
Bake in the preheated oven for 30 minutes. Remove from oven and place on a damp tea towel to cool.
mine didn't turn out as I hoped. Once reading the recipe over and over trying to figure out what I did wrong I see that you need to use TWO cake tins. I didn't have two so would have not picked this recipe to make. I changed to fan baked after the 30mins as it clearly wasn't set.
Cake is moist and yum to eat but the top was a little hard. Also I wasn't too sure I'f I needed to have soft butter or melted etc. recipe needing mode detail. - 26 May 2012