Preheat oven to 450° degrees. Prepare a large baking sheet with parchment. Slice biscuits in half. Generously butter each biscuit half and place on prepared cookie sheet. Sprinkle a spoon of Erythritol on each biscuit half and top with cinnamon. Bake in preheated oven for 5-10 minutes or until sweetener is bubbling and the edges of biscuits are golden brown. Broil for a minute if desired, for crispier biscuits (but watch carefully to prevent burning.)
Prepare a large baking sheet with parchment. Preheat oven to 350 degrees. Combine all dry ingredients in a mixing bowl. Mix in butter, cut into small pieces, and 1 egg. Add buttermilk. Flour baking surface with flour to prevent sticking. Use a rolling pin to roll out dough, about 1/2 to 3/4 inch thick. Use a cookie cutter to cut out biscuits and repeat with excess dough. Alternatively make drop biscuits by scooping dough onto parchment instead of rolling. Makes about 12 biscuits. Bake on prepared cookie sheet in preheated over for 15-20 minutes, or until golden brown.