Preheat oven to 350°F. Spray a mini muffin pan or donut pan with nonstick spray. Set aside.
In a large bowl, whisk together the flour, baking powder, baking soda, cinnamon, pumpkin pie spice and salt together in a large bowl. Set aside.
In a medium bowl, whisk together the egg, granulated sugar and brown sugar together until smooth. Whisk in the melted butter, milk, pumpkin puree and vanilla.
Pour the wet ingredients into the dry ingredients and gently stir with spoon. Be careful not to over-mix or your muffins will become dense. Whisk until all ingredients are just combined.
Fill each muffin cup 1/4 full. Dollop with a little bit less than 1/4 teaspoon of Nutella. Top with additional muffin batter filling the muffin cup 3/4 full. Smooth tops with back of spoon.
Bake in preheated oven for 10-12 minutes or until a toothpick inserted in the center comes out clean.
Meanwhile, make the topping. In a small bowl, mix the granulated sugar and cinnamon together.
Remove donut muffins from oven. Allow to cool for 10 minutes in the muffin tin before removing. Dip the top of the donut muffins into the melted butter and roll them into the cinnamon sugar coating. Repeat with all the muffins.