Heat waffle iron. Whisk together bake mix, sugar substitute, baking powder, baking soda, and cinnamon. Add buttermilk, eggs, butter and syrup; mix well. Batter will be stiff. Add cold water 1 tablespoon at a time until batter is spoonable.

Place approximately 3 tablespoons of batter in center of a waffle iron. Cook according to manufacturer's instructions until crisp and dark golden brown. Repeat with remaining batter.