Combine the sugar free cake mix, pumpkin, water, egg and cinnamon in a large bowl. Mix thoroughly.
Grease a muffin pan and fill up each cup with ¼ cup of the batter.
Bake at 325 degrees for 25 minutes.
Remove from oven and allow to cool.
Video
Notes
If you are a lover of that pumpkin chocolate flavor, you can substitute sugar free devil's food cake mix for the yellow cake mix.
Since this uses sugar-free cake mix, you will want to limit your consumption of the muffins to 1-2 a day. Sugar-free cake mix contains sugar alcohols which could have a laxative effect when taken in large quantities.
You can also you muffin liners for easier cleanup.