Cut off the top of the pumpkin and scrape out all the seeds. Place the butter or margarine and brown sugar inside the pumpkin and sprinkle with ground cinnamon. Put the pumpkin lid back on and place pumpkin in a baking pan with a little water in the bottom.
Bake at 350 degrees F (175 degrees C) for about 30 minutes or until tender. These can also be baked in the microwave on high for about 10 to 15 minutes.