Heat oven to 400°F. Spray 36 miniature muffin cups with nonstick cooking spray or line with paper baking cups. In large bowl, combine all-purpose flour, whole wheat flour, sugar, baking powder, baking soda, nutmeg, salt and allspice; mix well.
In small bowl, beat egg. Add buttermilk, banana and oil; mix well. Add to flour mixture; stir just until dry ingredients are moistened. Divide batter evenly into sprayed muffin cups, filling each 2/3 full.**
Bake at 400°F. for 10 to 15 minutes or until muffins are light golden brown and toothpick inserted in center comes out clean. Immediately remove from pan. Serve warm.