Line a square baking dish with parchment paper (8x8 dish other sizes may need more baking time).
Cut the cinnamon rolls into quarters and place them into the baking dish, spreading them around evenly. Set the icing from the packages aside.
For the pumpkin mixture, in a large mixing bowl, whisk together pumpkin puree, heavy cream, eggs, brown sugar, pumpkin pie spice, salt, and vanilla.
Pour the mixture over the cinnamon rolls.
Place the square dish on a baking sheet in case of overflow, and bake 45-50 minutes, until the cinnamon rolls are all cooked through. For best results, tent the dish with foil halfway through baking to prevent over browning the top
Allow the cinnamon roll bake to cool for about 5 minutes and then drizzle with icing.
Notes
Storage: Store covered in the refrigerator for up to 3 days and reheat individual portions in the microwave for 30-45 seconds or warm the whole dish in a 350°F oven for about 10 minutes.