I've made it before with splenda not sweet-n-low - got the idea on a thread in here - what might people not like about butter? Butter is great

The one thing is cinnamon has carbs - according to carb counter on this site, 25.5g per 100g - if you use a teaspoon, that's about 5g which is a bit over 1g of carbs. If you use a lot more cinnamon it'll be a lot more.