Preheat the oven to 350°F. Line a 9-inch square baking pan with parchment paper and lightly coat with baking spray. Press the cookie dough evenly into the bottom of the pan. Bake for 16–18 minutes, or until the edges are golden and the center is just set. Cool slightly.
In a medium saucepan, melt the butter over medium heat. Add the mini marshmallows and stir until smooth and fully melted.
Pour the marshmallow mixture evenly over the baked cookie base, spreading it to the edges. Immediately sprinkle the crushed Cinnamon Toast Crunch on top, pressing gently to help it stick.
Drizzle generously with caramel sauce and finish with a light dusting of cinnamon sugar.
Let the bars cool completely at room temperature (or chill to speed things up). Lift out using the parchment paper, slice into squares, and serve at room temperature.