Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the flour, pumpkin pie spice, baking powder, baking soda, and salt.
In another bowl, mix together the pumpkin puree, brown sugar, melted butter, and egg.
Gradually add the wet ingredients to the dry ingredients, mixing until just combined.
Drop spoonfuls of the batter onto a greased baking sheet.
Bake for 20-25 minutes, or until a toothpick inserted into the center comes out clean.
Let the buns cool on a wire rack before serving.