Preheat your oven to 350°F (175°C) and grease a mini muffin pan.
In a large bowl, mix together the pumpkin puree, granulated sugar, brown sugar, and eggs until smooth.
In another bowl, whisk together the flour, baking soda, cinnamon, and salt.
Gradually mix the dry ingredients into the wet mixture until just combined.
Prepare the cinnamon swirl by mixing additional sugar with cinnamon.
Pour batter into muffin cups, sprinkle cinnamon mixture, and layer more batter and cinnamon on top.
Bake for 15-20 minutes, or until a toothpick comes out clean. Cool before serving.