2. Whisk flour, sugar, baking powder, baking soda, and salt in bowl.
3. Mix banana, egg, spread, buttermilk, oil, and vanilla extract in large bowl until smooth. Gradually add flour mixture and stir until blended. Add 1/3 cup of the walnuts and mix thoroughly.
4. Fill muffin cups three-quarters full. Sprinkle remaining 2 tablespoons walnuts over tops.
5. Bake until a wooden pick inserted into center of muffin comes out clean, 15 to 20 minutes.
Info per muffin: 317 cal, 5 g pro, 39 g carb, 2 g fiber, 16 g fat, 3.5 g sat fat, 223 mg sodium