Spray the slow cooker crock with cooking spray.

Remove the cinnamon rolls from the tubes and cut in quarters (leave them rolled). Set the icing aside.

Place the cut cinnamon rolls in the bottom of the slow cooker. Don't crowd them together too much as they will expand. Just make a layer where they barely touch each other. Make a second layer with the extra.

In a mixing bowl add the eggs, milk, maple syrup, cinnamon, and vanilla. Whisk until well combined. Then pour the mixture over the cinnamon rolls.

Warm up one of the icing cups in the microwave for 7-10 seconds and drizzle it over the cinnamon rolls.

Cook on Low for 1½ to 2½ hours. Watch it so the bottom doesn't overcook.

When done, turn off the slow cooker and remove the lid.

Just before serving, warm up the remaining icing cup and drizzle the icing over the hot cinnamon roll casserole.

Serve a large spoonful with extra maple syrup, or some vanilla ice cream (or both!).