Preheat your oven to 350°F (175°C) and prepare a muffin tin.
In a large bowl, mix together pumpkin puree, oil, sugar, and brown sugar.
Add eggs to the mixture and stir until well combined.
In a separate bowl, whisk together flour, baking soda, baking powder, salt, and spices.
Gradually add the dry ingredients to the wet mixture, stirring until just combined.
If using, fold in chopped nuts gently into the batter.
Scoop the batter into the prepared muffin tin, filling each cup about two-thirds full.
Bake in the preheated oven for 18-20 minutes or until a toothpick comes out clean.
Allow muffins to cool in the tin for a few minutes before transferring to a wire rack to cool completely.