Preheat the oven to 160C. Grease 3 – 4 bread pans. Melt sugar and butter over a very low heat. Allow to cool slightly. Sift flour, baking powder and salt together in a VERY large mixing bowl. Add muesli and all-bran flakes. Mix well. Beat buttermilk and eggs. Mix in with the butter mixture. Add dry ingredients and mix into dough. Divide into the bread pans. Bake for 60 minutes. Remove from oven and allow to cool. Cut in top thick slices and dry overnight in oven at 50C.