Preheat oven to 350 degrees F. Lightly grease two mini muffin tins with cooking spray. Set aside.
For the muffins, in a large bowl, whisk together the pumpkin, granulated sugar, brown sugar, oil or butter, eggs and vanilla until well-mixed.
Add the flour, cinnamon, nutmeg, ginger, allspice, baking soda, baking powder, and salt. Mix until just combined and no dry streaks remain.
Scoop the muffin batter into the prepared pans, filling about ⅔ to ¾ full.
Bake the muffins for 9-11 minutes until the tops spring back lightly to the touch. Remove the muffins from the tin and let cool completely on a cooling rack.
For the topping, whisk together the sugar and cinnamon.
Dip the top of each muffin in the melted butter followed by the cinnamon and sugar. (Roll the top of the muffin around a second time in the cinnamon and sugar for a thicker coating, if desired.)
