Preheat over to 350 degrees. Butter two 1-pound loaf pans. Sift together the measures flour, baking powder, baking soda, and salt. Stir in macadamia nuts. In a separate bowl, cream butter and sugar. Beat in eggs and continue to beat until mixture is smooth. Stir in half the flour-nut mixture, and stir until well-blended. Divide batter into the prepared pans. Combine sugar and cinnamon. Sprinkle half the sugar-cinnamon mixture over batter in each pan and bake for 50 to 60 minutes, or until bread tests done. Let cool for 5 minutes, then turn out on cake rack to cool.