Pumpkin Banana Muffins

I used to make this bread all the time while I was in undergrad.  I have recently been craving pumpkin bread, and I had some overripe bananas to use up.  I halved the recipe, and made it into muffins instead.  It made 12 regular muffins and 12 mini muffins (that were a bit on the small side).  Now I just have to figure out what to do with the leftover pumpkin!

Pumpkin Banana Muffins (adapted from Spark People)
Ingredients:
1 1/2 cups all-purpose flour
1/2 cup whole wheat flour
1/2 tsp baking soda
2 tsp baking powder
1/2 tsp salt
1/2 tbsp pumpkin pie spice
2/3 cup sugar
1/3 cup packed light brown sugar
2 tbsp canola oil
2 eggs
1 overripe banana, mashed
3/4 cup pumpkin puree
1/2 cup buttermilk
Nonstick cooking spray

Directions:
Preheat oven to 350 F.
Mix the flours, baking soda, baking powder, salt and pumpkin pie spice in a large bowl, and make a well in the center.
Mix the sugars, oil, eggs, banana, pumpkin and buttermilk well, in a medium bowl.
Pour the liquid into the dry mixture, and fold together with a spatula until just combined.
Spray a standard muffin pan and a mini muffin pan with nonstick cooking spray.  Using an ice cream scooper, fill the standard muffin pan.  If there is leftover batter, fill the mini muffin pan.
Bake regular muffins 20 minutes and mini muffins 10 minutes.