1½ cups all-purpose flour
1 teaspoon baking powder
1 cup canned solid-pack pumpkin
1/3 cup vegetable oil
2 large eggs
1 teaspoon pumpkin-pie spice
1¼ cups (plus 1 tablespoon) sugar
½ teaspoon baking soda
½ teaspoon salt
1 teaspoon cinnamon
1/2 cup chocolate chips (optional)
Preheat oven to 350°
Put liners in muffin cups.
Whisk together pumpkin, oil, eggs, pumpkin-pie spice, 1¼ cups sugar, baking soda, and salt in a large bowl until smooth, then whisk in flour and baking powder 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 5 minutes, then transfer muffins from pan to rack and cool to warm or room temperature.
