Preheat the oven to 350°F (175°C). Line a 12-cup muffin pan with paper liners or lightly grease the cups.

In a large bowl, whisk together the flour, granulated sugar, brown sugar, pumpkin pie spice, baking soda, baking powder, and salt.

In a separate medium bowl, whisk the eggs, pumpkin puree, vegetable oil, milk, and vanilla extract until smooth.

Add the wet ingredients to the dry ingredients and stir just until combined. Do not overmix.

Fold in the chocolate chips and nuts, if using.

Divide the batter evenly among the muffin cups, filling each about 3/4 full.

In a small bowl, mix the 2 tablespoons granulated sugar and cinnamon, then sprinkle a little over the tops of the muffins.

Bake for 18 to 22 minutes, or until a toothpick inserted in the center comes out clean or with a few moist crumbs.

Let the muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.