Preheat oven to 400°.
Combine 1/2 cup oats, flour, and next 6 ingredients (flour through allspice) in a large bowl. Stir in pear, and make a well in center of mixture. Combine buttermilk and next 5 ingredients (buttermilk through egg), and stir well with a whisk. Add to flour mixture, stirring just until moist. Spoon batter into 18 muffin cups coated with cooking spray; sprinkle 1/2 cup oats evenly over batter.
Bake at 400° for 18 minutes or until done. Remove from pans immediately, and cool on a wire rack.