Preheat oven to 325°F (160°C).

Prepare muffin pans with liners or grease well for 24 cupcakes.

In a small bowl, whisk together flour, baking soda, baking powder, cinnamon, and salt.

In a large bowl, combine sugar and pumpkin puree.

Add oil to the pumpkin mixture and mix until well combined.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Fill muffin cups about 2/3 full.

Bake for 25-35 minutes, or until a toothpick inserted into the center comes out clean.

Let the muffins cool in the pan for a few minutes before transferring them to a wire rack to cool completely.