Heat the oven to 400°F (205°C). Use cooking spray to thoroughly coat a large 12-cup Bundt pan, then dust it lightly with flour.
Take the cinnamon roll dough out of the cans and slice each roll into four pieces.
In a medium bowl, combine the granulated sugar and ground cinnamon. Add the dough pieces and toss them until every piece is evenly coated with the mixture.
Arrange the coated dough pieces in the prepared Bundt pan.
In a small bowl, mix the brown sugar and vanilla extract into the melted butter. Drizzle this butter mixture evenly over the dough in the pan.
Bake for 25–35 minutes, until the center is no longer sticky. Take the pan out of the oven and allow it to cool for 10–15 minutes. While the bread is still warm but not burning hot, turn it upside down onto a serving plate to release the monkey bread.
Put the icing from the cinnamon roll cans into a plastic bag. With scissors, snip off a small corner, then pipe the icing over the entire surface of the warm monkey bread.