Preheat conventional oven to 350 degrees Fahrenheit. Lightly grease each well of a muffin pan with a bit of non-stick cooking spray. You can also line your muffin pan with muffin liners or parchment paper liners. Set aside.

In a large mixing bowl, combine brown sugar, flour, salt, baking soda, and ground spices. Make a well in the center of the dry ingredients. Set aside.

In a medium mixing bowl, whisk together the wet ingredients. Make sure the eggs, melted butter, vanilla, and pumpkin puree are well combined.

Add the pumpkin mixture to dry ingredients. Stir until just combined. Do not overmix.

Divide batter among prepared muffins cups. About a couple tablespoons per muffin well. Aim to fill about ⅔ of the way to allow room for muffins to rise while baking.

Bake muffins at 350 degrees F for 20-25 minutes, or until toothpick inserted in the center of a muffin comes out clean.

Let cool in the pan about 15 minutes, then transfer to a wire rack to cool to room temperature.