Add the water, yeast, and granulated sugar in a small bowl and stir to combine. Let sit for about 5 to 10 minutes until the mixture becomes foamy.
In a large bowl, add 4 cups of flour and cake mix. Stir to combine.
Pour in the yeast mixture and stir until the dough comes together.
Add the remaining flour a ½ cup at a time until a soft dough has formed, you may not use all of the flour.
Place the dough into a large well-greased bowl, cover loosely with plastic wrap or a towel.
Let the dough rise until it has doubled, about 30 minutes to 1 hour.
Punch the dough down and roll it out onto a clean, floured surface.
Sprinkle flour on the top of the dough and rolling pin.
Roll the dough out into a 10x16 inch rectangle that's about a ¼ to ½ inch thick.
Brush the melted butter all over the top of the rolled out dough.
Add the brown sugar and cinnamon to a small bowl. Stir until combined.
Sprinkle the cinnamon and sugar on the melted butter.
Roll the dough up starting from one of the long sides. Press the ends of the dough in to make the ends thicker.
Slice the dough into 13 to 14 1-inch thick rolls.
Grease the bottom and sides of a 9x13 inch pan.
Place the rolls into the prepared pan and loosely cover with plastic wrap.
Let the rolls rise until they have almost doubled, about 15 to 20 minutes.
Place into the oven and bake at 375 degrees for 10 to 15 minutes or until the tops are slightly browned and if you carefully tug on one of the center rolls, it's not doughy.
Remove from the oven and begin making the frosting.
Frosting
Add the cream cheese and butter into a large bowl. Beat with a hand mixer until creamy. Scrape the sides of the bowl.
Add in the powdered sugar, heavy cream, and vanilla extract. Beat until the frosting comes together and is creamy. The frosting will be thick.