Preheat oven to 350 degrees F. Stir together flour, baking powder, spices, baking soda, and salt. Set aside. In a large bowl, beat eggs until light. Gradually beat in brown sugar and honey until mixture is light and fluffy. Slowly beat in oil. At low speed of mixer or with rubber spatula, stir in flour mixture alternately with yogurt. Lightly but thoroughly stir in zucchini, walnuts, banana, and orange peel.
Turn batter into a greased, floured 9- or 10-inch fluted tube pan. Bake 50 to 60 minutes. Cool 10 minutes, then invert on rack and remove from pan. Cool completely. Spread with Cream-Cheese Honey Glaze or confectioners’ sugar.