Measure out and prepare all of the ingredients.

In a microwave safe bowl, melt the butter.

Add the pumpkin puree and egg with the melted butter.

Stir to combine well.

Add in the coconut flour, erythritol, baking powder, and pumpkin pie spice.

Stir until everything is combined well. Place in the microwave and set it for 2 minutes or until the cake is brown on top and sides.

Let cool a bit before serving. Top with whipped cream and cinnamon. Enjoy!