Butter 2 (8x4-inch or 9x5) loaf pans or spray with baking spray, then line with parchment paper. Remove filling from the refrigerator.
Turn the chilled dough out onto a lightly floured surface. Divide the chilled dough in half, and return one dough ball to the refrigerator. Roll the other dough out into a 12x16-inch rectangle.
Using an offset spatula, spread half of the chocolate filling over the dough, leaving a 1-inch border free on one of the long ends of the sheet.
Starting opposite the 1-inch border free filling, use both hands and slowly roll the dough over the filling to create a log. When you get to the edge of the dough, press the bare border to seal the dough log.
Starting 1-inch from one end, and using a sharp knife, slice the babka roll in half lengthwise, exposing the filling. Position the dough cut side up.
Braid the two strips of dough together by folding one half over the other to form a twisted braid. Pinch each end of the braid together to seal.
Carefully transfer the braided babka to the prepared loaf pan. If the babka braid is too long to fit in the pan, squeeze to condense or twist it into a figure-eight formation before placing it inside.
Cover the babka with a clean kitchen towel and let it rest in a warm spot until it doubles in size, about 1 1/2–2 hours.
Preheat the oven to 350°F.
Transfer the babka to the oven and bake 40 minutes or until the crust is golden brown and a wooden toothpick can be inserted into the center without resistance and comes out clean.