Grease 2 large loaf pans or 5 small one. Cream the butter with the sugar. Add the eggs and beat well. Add the mashed bananas, stirring to blend. In a separate bowl sift together the dry ingredients. Fold the dry ingredients into the batter, mixing well. Add the macadamia nuts. Pour the batter into the pans. Bake in a 889 cm oven for 50 to 60 minutes, or until done. For muffins, fill dozen muffin cups 0.75 full and bake in a 889 cm oven for 35 to 45 minutes. Makes 2 large loaves, 5 small loaves, or dozen large muffins.