In a pot, start to melt the butter then add the chocolate and stir until smooth. Turn off the heat and add the cinnamon, salt, vanilla, cocoa and powdered sugar and mix to combine. If it’s thick you can heat it up a bit again or add a bit of milk. You don’t want it runny, just spreadable.
Grease a 13x9” cake pan. On a floured countertop, set the dough and roll it out to a large rectangle, about 13x20”. Spread the filling over the dough, then roll up from the shorter side (so you have a long log).
Using a bread knife or unwaxed dental floss, slice the log into 1” rounds. Place on the prepared cake pan. Arrange so the rolls have enough space to both rise and rise again later when they bake (I find placing them like this: 2,1,2,1,2..etc works best).
Cover with a tea towel and let rise for another 45-60 minutes, until you can press the dough and it slowly bounces back but leaves an indentation. (If it bounces back immediately, it’s not ready to be baked). Alternatively, leave the rolls in the fridge overnight, they might not fully rise and you can do the remaining rise at room temp while the oven preheats.
Preheat the oven to 350 F. Pour the heavy cream over the rolls and bake for about 35 minutes, until they are golden (bake time will vary based on your oven and pan, check them at 25 minutes).
Whisk all the glaze ingredients together. If you are adding cocoa you might need a bit more milk to thin it out.
You can glaze immediately for a thin runny/gooey roll or you can wait until they cool, pour the glaze or spread over the rolls.
Serve warm! The rolls will keep overnight in an airtight container, microwave them for 30 seconds to warm them up.