Preheat your oven to 400°F. Using 2 muffin pans, line every other cup with muffin liners, spacing them out. Set pans aside.
In a large bowl, whisk together the vegetable oil, pumpkin puree, granulated sugar, light brown sugar, eggs, milk, and vanilla extract.
In a separate bowl, whisk together the flour, baking powder, baking soda, salt, pumpkin pie spice, and cinnamon until combined.
Dump the dry ingredients into the bowl with the wet ingredients. Use a spatula to gently fold everything together. Fold until just combined. *Do not over mix
Fill the lined muffin cups halfway with muffin batter. Drop a spoonful of Nutella (about 2 teaspoons) in the center of each cup. Spoon or scoop out the remaining muffin batter evenly between all the muffin cups.
Drop a teaspoon of Nutella onto the tops of each muffin. Using a toothpick or a butter knife, or something similar, drag it through the Nutella and muffin batter to create a swirled effect.
Pop in the oven and bake the muffins for 16-20 minutes. They should spring back to the touch. Allow the muffins to sit in the pan for a few minutes, then transfer them to a cooling rack.