Remove babka dough from the refrigerator, divide in half, and roll out to a 24 x 18 inch rectangle on a lightly floured counter.
You should now have two rectangles rolled out in your kitchen. With a pallet knife gently spread chocolate babka filling on the first rolled out dough. Leave a 1-inch gap around all sides.
Do the same with your cinnamon babka filling on the second rolled out dough. Be sure to leave a 1-inch gap around all sides.
Roll each rectangle into a long log, and place in the freezer for 15-20 minutes or until firm.
Remove both dough rolls from the freezer, and using a sharp bread knife, cut down the middle lengthwise, exposing all the chocolate/cinnamon layers.
Hold the two halves of dough against each other so the cut sides are facing out, and twist into a decorative loaf. Place in buttered, parchment-lined loaf pans, cover with a damp towel, and allow to rise in the off oven for 2 hours.
Preheat oven to 375°F and bake for 30-40 minutes, or until a tester inserted into the thickest part of the loaf comes out clean. Remove from the oven, place on wire racks, and immediately brush down with simple syrup. Allow to cool for at least an hour before slicing and serving.