Cut each leftover cinnamon roll in half horizontally.
In a medium bowl, whisk together the eggs, heavy cream, sugar, vanilla extract, and ground cinnamon until smooth.
Dip each halved cinnamon roll into the egg mixture, coating both sides well.
Heat a nonstick skillet over medium heat and add a bit of butter. Cook the dipped cinnamon rolls for 2–3 minutes per side, or until golden brown and slightly crisp.
Transfer them to a serving platter and serve warm with maple syrup and a dusting of powdered sugar.