Whisk Bisquick, egg, vanilla, and milk until thin. The batter will be very thin and will drip easily off a spoon.

Heat a small 7-8" frying pan over medium-low heat. Spray with cooking spray (or grease with butter) and add about 1/8 cup of batter in the pan. Swirl the pan to spread the batter into a large thin circle (like you're making a crepe). Cook until the top is filled with bubbles and you can easily flip the pancake. Cook for just a few seconds more then place on a plate. Repeat until all batter is gone.

Stir the sugar and cinnamon in a small bowl. You can add more cinnamon if you'd like; we like it more sweet so I use less cinnamon. (Optional: spread each pancake with butter.) Sprinkle some cinnamon sugar mix on each pancake and roll up. Serve warm.