Measure out a 30 inch by 10 inch rectangle on your work surface; mark the parameters with tape or utensils. This will tell you how far you need to roll out the dough.
Generously flour your work surface and rolling pin, then scoop the chilled, risen dough onto the work surface. Roll the dough as best you can into the rectangular shape you’ve marked on the work surface; the shape doesn’t need to be perfect since you’re not cutting the dough into rolls.
Once the dough is the desired shape, drizzle the melted butter all over the dough and spread it around with a spatula, edge to edge. Then sprinkle the cinnamon sugar mixture evenly all over the buttery dough.
Time to roll: starting from the farthest, long end of the rectangle, slowly roll the dough as tightly as possible into a log. Don’t worry about making it perfect or if the roll is a little loose; it doesn’t matter!
Fold the dough log in half and dump it into your prepared baking dish, tucking it in to make sure its completely contained within the dish. No need to make it pretty at this stage since it will rise up as one, big loaf and be filled with spirals when you cut into it!
Cover the baking dish with a clean tea towel and place in a warm area to let dough rise for 20 minutes.
Remove the tea towel and place the baking dish into the oven. Bake at 325F for 40-45 minutes, or until the top is deep golden brown and feels solid to the touch when lightly pressed.
While the cake is baking, make the icing: whisk all icing inredients together until you have a thick paste. Set aside.
Remove Cinnamon Roll Cake from oven. Immediately spread the orange vanilla icing onto the cake so it melts. Let Cinnamon Roll Cake cool about 5 minutes, then cut and serve.