Preheat the oven to 350°F and grease a 12-cup capacity bundt pan really well with cooking spray. Pop open each can of cinnamon rolls and set aside on a cutting board.
Combine the granulated sugar with the cinnamon in a bowl or a zip top bag. Set aside.
Cut each cinnamon roll into quarters and gently roll the pieces in the cinnamon sugar until fully coated. Arrange them evenly in the bottom of the bundt pan.
Sprinkle any remaining cinnamon sugar over the top and gently shake the pan to help coat the cinnamon roll pieces evenly.
Next, make the glaze. In a small saucepan over medium heat, melt the butter, brown sugar, and salt together. Bring to a gentle simmer and cook for about 30 seconds, or until the sugar dissolves.
Pour the butter-sugar mixture evenly over the cinnamon bun pieces in the pan. Swirl the bundt pan around to make sure the glaze coats all the cinnamon roll pieces evenly and gets into every nook and cranny.
Bake at 350°F for 30–40 minutes, or until the center has risen and is no longer doughy. To test, pull a piece from the middle—if it comes away cleanly, it’s done. If it’s still stretchy or gummy, bake a little longer. If you have an instant-read kitchen thermometer, the monkey bread will be done when the center reaches 190°F. Let the cinnamon bread cool in the pan for 5 minutes.
To get it out of the pan, place a plate or serving dish over the bundt pan and carefully flip it so the cinnamon bread releases onto the plate. Do this while the bread is still hot and before the glaze sets. It's much easier to get out that way. Let it cool for another 10 minutes before icing.
After cooling, drizzle some of the leftover cinnamon roll icing over the monkey bread (you won't need all of it). Stir or gently warm the icing to make it easier to drizzle, or use a piping bag if you prefer. Serve your cinnamon pull apart bread warm with extra icing on the side.