In a medium bowl, combine the melted butter, brown sugar, granulated sugar, cinnamon, and Baking Salt.
Using an offset spatula, spread the filling evenly over the rolled-out dough.
Starting at the long end of the dough, roll it into a log. Pinch the seam shut. Flip the seam side down.*(see notes for shaping traditional cinnamon buns)
Use a sharp knife to cut the dough in half down the length of the log, stopping just short of the end.
To create the swirl, overlap the two pieces of dough, keeping the cut side up at all times, so the filling won’t fall out. Once the bread is twisted all the way to the bottom, pinch the ends together. Cut the end that you left intact, then twist and pinch together that end.
Wind the ends into the center, going in opposite directions to create two opposing spirals.
Butter a 12-inch skillet and place the swirled dough into it. Cover with plastic and allow to rest for about 1 hour** or until it puffs up and when you poke the dough it no longer springs back. Pro Tip: If your kitchen is cool, put the dough into the oven with just the light on. Preheat the oven to 350°F. Rack should be in the middle of the oven.
Place the skillet on a baking sheet and bake for about 35 to 40 minutes or until caramel brown on top and set in the middle. Pro Tip: If the dough on top starts to get too brown, loosely drape a sheet of foil over the top. Don’t tuck it around the dough or you will steam the bread.