Banana-walnut muffins

Butter, unsalted, softened	½ cup
Sugar	1 cup
Vanilla	1 teaspoon
Eggs	2
Bananas, ripe, mashed	3 to 4
Flour, whole wheat + all-purpose baking	¾ cup + ¾ cup
Baking soda	¾ teaspoon
Cinnamon, ground	1 ½ teaspoons
Nutmeg, freshly ground	¼ teaspoon
Salt	½ teaspoon
Walnuts, chopped	1 cup
Brown sugar

1. Preheat oven to 350°F; spray muffin tin, or line with paper cups.
2. Cream butter, add sugar and vanilla, and then eggs, one at a time; stir in bananas.
3. In a separate bowl, whisk together flours, soda, cinnamon, nutmeg, and salt.
4. Gently combine wet and dry mixtures together, and then fold in nuts.
5. Pour into prepared muffin tin, and sprinkle with brown sugar.
6. Bake for 20 to 25 minutes.