Add all the cinnamon roll dry ingredients to a small bowl and grease two mugs. Stir with a spoon to combine. Add the butter and egg and mix until smooth. Divide the batter in half and evenly add to each mug.
In a separate bowl, mix the frosting ingredients together (cream cheese, butter and powdered sweetener). Adjust the amount of sweetener to taste. Add a little almond milk depending on if you want a thicker or runnier frosting.
Microwave each cinnamon roll mug on high for 60 - 90 seconds until just set. Mine took 60 seconds in a 900W microwave.
Top each cinnamon roll mug cake with frosting and enjoy!