Preheat the oven to 425°F/218℃. Line the muffin tin with liners and set aside. This recipe makes 15 muffins total. In a small bowl, mix cinnamon and sugar and set aside. This will be used for the topping.
2 tbsp white sugar, 1/2 tsp cinnamon
In a medium-sized bowl, add in the dry ingredients. Stir together and set aside.
1 3/4 cups all-purpose flour, 1 1/4 cups rolled oats, 1 tsp baking soda, 1 1/2 tsps baking powder, 1 1/2 tsps cinnamon, 1/4 tsp ginger, 1/8 tsp allspice, 1/8 tsp nutmeg, 1/2 tsp salt
In a large bowl, add brown sugar, white sugar, oil, eggs, pumpkin, sour cream, and vanilla. Whisk together until well combined.
1 cup pumpkin puree, 3/4 cups dark brown sugar, 1/4 cup white sugar, 1/2 cup sour cream, 2/3 cups oil, 2 large eggs, 2 tsps vanilla
Add the dry ingredients into the wet ones and with a spatula, gently mix it together to create a soft muffin batter. Once no dry streaks are showing, stop mixing.
Evenly divide the batter between the liners, they should be almost or all the way full. Using a cookie scooper helps big time to minimize the mess. Sprinkle cinnamon sugar on top.
Bake the muffins at 425℉ for 5 minutes, then lower the oven to 375°F and continue baking for 15-20 minutes. The muffins are ready when a toothpick inserted comes out clean with no wet batter. Every oven differs, so keep an eye out after the 15 minute mark.
These muffins are best served fresh and can be stored in the refrigerator for up to 1 week.