In a large stockpot, cook pumpkin puree with flour, maple syrup, pumpkin pie spice, and sugar for 5-10 minutes over medium heat until thickened. Remove from heat.
In a separate stockpot, brown butter until golden and toasted. Add your ground cinnamon, ground ginger, and ground nutmeg. Strain to remove any burnt bits and let cool slightly.
Add your brown butter, egg, and brown sugar to your pumpkin puree mixture.
In a large bowl combine flour, baking soda, baking powder, and salt.
Add flour mixture to pumpkin mixture with a wooden spoon. Mixture should be stiff and thick. Place in the fridge to chill for 2-3 hours.
Preheat oven to 350°F. Scoop 10-12 large balls of cookie dough onto parchment-lined baking sheets. The balls should be the size of a meatball, or about 1/3 cup.
Sprinkle tops with sea salt and bake for 15-20 minutes. Cool for 30 minutes and transfer to a wire rack.