Preheat the oven to 350°F. Lightly grease a 9 x 13-inch baking dish with nonstick cooking spray.

Set the icing packets from the cinnamon rolls aside for later.

Cut each cinnamon roll into 4 equal pieces.

Arrange the cinnamon roll pieces evenly in the prepared baking dish.

Add the pumpkin purée, eggs, milk, brown sugar, vanilla extract, pumpkin pie spice, cinnamon, salt, and melted butter to a large mixing bowl.

Whisk until the pumpkin mixture is smooth and thoroughly combined.

Pour the pumpkin mixture evenly over the cinnamon roll pieces, making sure the pieces are well coated.

Gently press the cinnamon roll pieces into the pumpkin mixture so they can absorb some of the custard.

Bake for 30 to 35 minutes, or until the cinnamon rolls are golden brown, the center is set, and the dough is cooked through.

Remove the casserole from the oven and let it cool for about 5 minutes.

If needed, warm the reserved icing packets for a few seconds to make the icing easier to drizzle.

Drizzle the icing evenly over the warm pumpkin cinnamon roll casserole.

Serve warm.