Ever so slightly adapted from Ms. Deb at Smitten Kitchen
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
2 large eggs
1 teaspoon pumpkin-pie spice
3/4 cup white sugar
1/2 cup light brown sugar ** these were my changes, I ran out of regular sugar
1/2 teaspoon baking soda
1/2 teaspoon salt
1 teaspoon cinnamon
Put oven in middle position and preheat oven to 350°F. Put liners in muffin cups.
Whisk together pumpkin, oil, eggs, pumpkin pie spice, 1 1/4 cups sugar, baking soda, and salt in a large bowl until smooth, then whisk in flour mixture until just combined.
Stir together cinnamon and remaining 1 tablespoon sugar in another bowl.
Divide batter among muffin cups (each should be about three-fourths full), then sprinkle tops with cinnamon-sugar mixture.
Bake until puffed and golden brown and wooden pick or skewer inserted into the center of a muffin comes out clean, 25 to 30 minutes.
Cool in pan on a rack five minutes, then transfer muffins from pan to rack and cool to warm or room temperature.