Preheat the oven to 350°F (175°C) and line a 12-cup muffin tin with paper liners.
In a large mixing bowl, combine the pumpkin puree, vegetable oil, brown sugar, granulated sugar, eggs, and vanilla extract. Whisk until the mixture is smooth and well combined.
In a separate bowl, whisk together the all-purpose flour, baking soda, baking powder, ground cinnamon, ground nutmeg, ground ginger, and salt.
Gradually add the dry ingredients to the wet mixture, stirring until just combined. Avoid over-mixing to keep the muffins tender.
If using, fold in the chopped nuts and chocolate chips until evenly distributed throughout the batter.
Distribute the muffin batter evenly among the prepared muffin cups, filling them about 2/3 full.
Bake in the preheated oven for 20-25 minutes, or until a toothpick inserted into the center comes out clean.
Remove from the oven and allow to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely.
Notes
Serve warm, dusted with powdered sugar and garnished with cinnamon and candied pecans.