Preheat the oven to 350 degrees.
In a stand mixer fitted with the paddle attachment or a hand mixer, beat the butter and sugar until light and fluffy.
Add in pumpkin puree and eggs, mix until combined. Scrape down the bowl once complete.
In a separate bowl, whisk together dry ingredients (flour, pumpkin pie spice, salt, baking soda, baking powder).
Slowly add the dry ingredients to the wet ingredients, mixing in between each addition. Scrape down the bowl once complete.
Prepare the muffin tin by lining with paper cupcake liners OR greasing it well.
Use a spoon or a cookie dough scoop to spoon the batter into each muffin well. Fill each ~¾ full.
Mix sugar and cinnamon together in a medium-sized bowl. Set aside.
Bake for 18-20 minutes or until a toothpick comes out clean.
Remove from the oven and let rest for 2-3 minutes. Then remove the muffins from the tin and toss in sugar mixture while still warm (remove paper liners if desired, otherwise just dip the tops in the sugar mixture).
Store at room temperature.