Preheat oven to 350°F and spray 9×13-inch baking dish with nonstick spray
Open cinnamon roll cans, set aside icing packets, arrange rolls in dish
Pour 1 cup heavy cream over and between rolls
Melt 4 tablespoons butter, mix with ⅓ cup brown sugar and ½ teaspoon cinnamon
Pour butter-sugar mixture evenly over rolls
Cover dish with foil, bake 30-40 minutes
Remove from oven, rest 5 minutes
Mix 4 tablespoons butter and 4 ounces cream cheese in bowl, microwave 30 seconds
Whisk butter-cream cheese mixture until smooth
Add reserved icing packets and 1 cup powdered sugar, whisk until smooth
Spread icing over warm rolls
Serve immediately while warm