This recipe uses applesauce in place of some of the butter or oil to make these muffins a healthier treat. For the richest flavor, use overripe bananas.
Put flour, baking soda, cardamom, cinnamon, nutmeg, and salt into a large bowl; set aside. Put sugar and butter or oil into a second large bowl and beat with an electric mixer until well combined. Add bananas, applesauce, zest, vanilla, and egg to the sugar-butter mixture, and beat again until combined. Add flour mixture to banana mixture in three parts, stirring well after each addition; fold in walnuts.
Spoon batter into prepared tin; bake until a toothpick inserted in the center of a muffin comes out clean, about 25 minutes. Serve warm or at room temperature.
Recipe adapted from The Tassajara Bread Book , by Edward Espe Brown, copyright © 1995 (with permission from Shambhala Publications, Inc.)