Gaston's Giant Cinnamon Rolls

Dough
3/4 cup salted butter, melted, divided
1½ cups whole milk
6½ cups all-purpose flour, divided
2 (1/4-ounce) packets active dry yeast
1/2 cup granulated sugar
1 teaspoon salt
1/2 cup water, at room-temperature
2 large eggs

Filling
2 cups light brown sugar
2 tablespoons ground cinnamon
1 cup salted butter, softened

Cream Cheese Frosting
8 ounces cream cheese
1/4 cup salted butter, softened
2 cups powdered sugar
1 teaspoon vanilla extract
3 tablespoons heavy cream
1/8 teaspoon salt

Butterscotch Topping
1/2 cup light brown sugar
4 tablespoons salted butter, softened
1/2 cup heavy cream
1/4 teaspoon salt
1 teaspoon vanilla extract

For the dough:

Grease a 9x13-inch pan with nonstick cooking spray and set aside.
In a medium bowl, combine 1/2 cup melted butter and milk.
In the bowl of a stand mixer, add 2½ cups flour, yeast, sugar and salt. Add water, egg and butter mixture. Using the flat beater attachment, mix until well-combined. Add remaining flour, 1/2 cup at a time, while mixing until the dough starts to form a ball.
Switch to the dough hook attachment and knead on low speed, 5 minutes.
Remove dough from bowl, sprinkle some flour in bowl and place dough back in the same bowl. Let rise 10 minutes in a warm place.

For the filling:

In a medium bowl, mix brown sugar, cinnamon and butter together. Set aside.

To assemble:

Roll out dough into a long rectangle, about 3- by 2-feet. Spread filling evenly across the whole surface of the dough. Starting at short end, roll dough like a jelly roll. Make a cut in the center of the roll, and then cut about 6 inches from the center on either side to make 2 giant rolls.
Place both rolls swirl-edge down in prepared pan.
Preheat oven to 375 F.
Drizzle remaining 1/4 cup melted butter over rolls. Allow rolls to rise at room temperature, 30 minutes.
Bake rolls 20 minutes, then cover loosely with foil and bake another 10 minutes.

For the cream cheese frosting:

In a medium saucepan over medium heat, add cream cheese and butter. Combine and heat until melted, about 3 minutes. Remove from heat and stir in powdered sugar. Add vanilla, cream and salt. Stir, then set aside.

For the butterscotch topping:

In a separate medium saucepan over medium heat, add brown sugar, butter and cream. Bring to a boil and boil 5 minutes, stirring frequently. Remove from heat. Add salt and vanilla. Set aside.

To serve:

Place each giant roll on a large plate. Drizzle cream cheese frosting in one direction along each roll's swirl, then drizzle with butterscotch in the other direction.