Preheat the oven to 350 degrees Fahrenheit. Spray a 9 x 13-inch baking dish with nonstick cooking spray and set aside.
Without breaking the rolls apart, slice 1 (12-count) package Hawaiian rolls in half horizontally. Carefully lift the top half off the bottom half, keeping both halves intact. Place the bottom half of the rolls cut-side up in the prepared baking dish.
Spread 5 tablespoons of the ½ cup softened salted butter over the bottom half of the rolls.
Combine ⅔ cup brown sugar, 1 tablespoon ground cinnamon, and ⅙ teaspoon salt in a small bowl and sprinkle about ⅔ of the mixture evenly on top of the butter. Place the top half of the rolls onto the cinnamon sugar, then spread the remaining 3 tablespoons of butter over the top, followed by the remaining ⅓ of the cinnamon sugar.
Cover with aluminum foil and bake for 12 minutes. Remove the foil and bake for an additional 5 minutes to brown the tops.
While the rolls are baking, prepare the frosting by using a hand mixer to beat 2 ounces softened cream cheese, 1 tablespoon softened salted butter, 1 cup powdered sugar, and 1 teaspoon vanilla extract together in a medium bowl until smooth.
Let the rolls sit for 2-3 minutes before spreading the frosting over them and serving.
Notes
Storage: Keep leftovers in an airtight container or tightly wrapped in the fridge for up to 5 days.
Reheat: Warm in the microwave in 20–30 second bursts until heated through.
Make Ahead: Assemble through step 4, cover, and refrigerate overnight. Add 3–4 minutes to the bake time the next day.