Preheat oven to 350 degrees. Grease and line a 9x5x4 load pan. Set aside.
Combine flour, bran flakes and seasonings in a bowl. Set aside.
Beat together eggs, sugars, oil, applesauce and vanilla. Slowly add in flour mixture and combine so no flour shows. Add grated carrot and zucchini and mix to combine. Add raisins and nuts, which are optional.
Pour into prepared pan. It will be very full, but loaf does not rise very much.
Bake approximately 1 hour and 20 minutes or until cake tester comes out clean. Cool in pan on rack 10 minutes then remove from pan and allow to cool completely. Keeps very well, wrapped in fridge.