How to Make It
Preheat oven to 350°F. Line a 12-cup muffin pan with paper baking cups; lightly coat cups with cooking spray.
Sprinkle 1 cup of the walnuts on a baking sheet. Bake in preheated oven until lightly toasted, 5 to 6 minutes. Remove from oven, and let stand until ready to use.
Whisk together kamut flour, whole-wheat flour, baking powder, allspice, and salt in a large bowl. Stir together mashed banana, sugar, butter, milk, and eggs in a medium bowl. Add banana mixture to flour mixture; stir just until combined. Stir in toasted walnuts.
Divide batter evenly among prepared muffin cups. Sprinkle tops of muffins with banana chips and remaining ½ cup walnuts. Bake at 350°F until a wooden pick inserted in center comes out clean, 20 to 22 minutes.
Remove from oven, and cool in pan 5 minutes. Serve muffins warm or at room temperature.