Preheat the oven to 375°F. Coat the muffin tin with cooking spray or butter (optional: use muffin paper liner).
In a bowl: add flour, salt, cinnamon, pumpkin spice, baking powder & baking soda. Mix everything together. (I highly recommend sifting the dry ingredients before adding to the wet ingredients, this will make the batter fluffy and not lumpy).
1 ½ cup all-purpose flour (215g), 2 tsp pumpkin spice, 1 tsp baking powder, ½ tsp ground cinnamon, ½ tsp salt, ½ tsp baking soda
In a large separate bowl: add white sugar, brown sugar, eggs, vanilla extract, pumpkin puree and oil. Mix everything together until combined. Add dry ingredients and mix.
½ cup granulated sugar, ½ cup brown sugar, ½ cup vegetable or canola oil , 1 tsp vanilla extract , 15 oz pumpkin puree (not pumpkin filling), 2 large eggs
Use an ice cream scooper or spoon to measure even portions. Place each scoop of batter in the muffin tin (should be exactly 12 scoops).
Bake for 20-22 minutes or until lightly golden brown. Let the muffins cool in the tin for about 5 minutes and then transfer them to a baking rack to finish cooling completely.