I found a recipe online and it evolved. Here is the original link: http://smittenkitchen.com/2006/10/promise-keeper-pumpkin-eater/
And here is how I make it:
1 1/2 cups all-purpose flour
1 teaspoon baking powder
1 cup canned solid-pack pumpkin (from a 15 ounce can)
1/3 cup vegetable oil
1 large egg
1 mashed banana
1 teaspoon pumpkin-pie spice (I made my own blend using 1 1/2 teaspoon cinnamon, 1/2 teaspoon ground nutmeg, 1/4 teaspoon ground cloves, 1/2 ground ginger (scant)
1 cup sugar
1/2 teaspoon baking soda
3/4 teaspoon large crystal sea salt
Place oven rack in middle position and preheat oven to 350°F. Prepare a standard 12 muffin pan. (I use canola spray oil.)
Stir together flour and baking powder in a small bowl.
Whisk together pumpkin, oil, eggs, pumpkin pie spice, 1 cup sugar, baking soda, and salt in a large bowl until smooth, then whisk in flour mixture until just combined.
Divide batter among muffin cups (each should be about three-fourths full).
Bake until puffed and golden brown and wooden pick or skewer inserted into the center of a muffin comes out clean, 25 minutes.
Cool in pan on a rack five minutes, then transfer muffins from pan to rack and cool to warm or room temperature.
You'll have leftover pumpkin pie spice. I mix it with sugar and use it in my latte with honey. You can also mix with sugar and sprinkle on muffin tops before baking.
You will also have enough pumpkin to make two batches, so you might plan on pumpkin muffins two days in a row!