Preheat the oven to 350 degrees. While it heats, slice the dinner rolls in half and arrange the bottom halves in a 13" x 9" baking dish.
Spread a tablespoon of butter on each bottom roll, then top each with a marshmallow. Place the dish in the oven and toast until the marshmallows turn golden brown, about 2–3 minutes.
Remove the bottom rolls from the dish and let them cool for 5 minutes. Meanwhile, place the top halves of the rolls in the baking dish, top side down, butter each one, and toast in the oven until golden brown, about 3-5 minutes.
Layer the Pretzel Snaps on the bottom rolls, drizzle with caramel sauce, and sprinkle with flaky salt. Finish by placing the toasted roll halves on top.
Slice and serve immediately!