Peanut Butter and Banana Muffins

These were a big hit!!

1 1/2 cup all-purpose flour
1/2 cup quick cooking oats
3/4 cup packed brown sugar
1 tablespoon baking powder
1 cup milk
2/3 cup peanut butter
1/2 cup mashed ripe banana (I used 1 1/2 bananas)
1 egg, beaten
2 tablespoons vegetable oil
1 teaspoon vanilla extract
3/4 bag of peanut butter chips 

  1/4 cup all-purpose flour
2 tablespoons butter, melted
2 tablespoons packed brown sugar (I actually didn't make this topping; I drizzled chocolate on top as per one comment's suggestion.)

Directions
1. Preheat oven to 375 degrees F (190 degrees C). Grease 12 muffin cups or line with paper muffin liners.
2. Combine flour, oats, brown sugar, and baking powder.
3. Whisk together milk, peanut butter, banana, egg, oil, and vanilla. Add banana mixture to dry ingredients, mixing just until moistened. Fill prepared muffin cups 3/4 full.
4. In a small bowl, stir together 1/4 cup flour, melted butter and 2 tablespoons brown sugar. Sprinkle topping evenly over muffins, if using.
5. Bake in preheated oven for 18 minutes, until golden brown. Drizzle chocolate over, if desired.
Serve warm.
I also found that this recipe made about 16 muffins, not 12; bonus!