Preheat the oven to 350°F. Line a standard muffin tin with paper muffin liners.
In a large bowl, sift together the flour, baking soda, cinnamon, nutmeg and baking powder. In a second bowl, whisk together the sugar, oil and eggs. Add the pumpkin and sugar mixture to the dry ingredients and whisk just to combine. Do not overmix.
Fill the muffin cups ⅔ full and bake for 25 to 30 minutes or until a toothpick inserted in the center comes out clean. Serve warm or cool to room temperature and frost with cream cheese if desired.