Place it on a surface barely dusted with flour. And start rolling it.
Roll it into a 12”x16” rectangle. Use a knife to trim the sides if you want. You can roll the trimmings and bake them. (or let your 3 year old play with them, if you are me)
From the shortest side, start to roll up the dough into a log.
Place the log in the fridge for at least 30 minutes. Trust me on this one, it will make the process much cleaner and less messy, and your babka will look way better once baked, since the filling won’t have leaked everywhere.
You will end up with two halves like this.
*I really recommend letting the dough rest in the fridge overnight for best results. However, if you want to make this on the same day, you can let the dough rise on the counter for about 2 hours, and then place it in the fridge for another 2 hours. The quality won’t be the same, but it will save you some time if you are in a pinch.