Line the bottom of the 2 8" loaf pan with parchment paper and grease the sides.
On a lightly floured surface, divide the babka dough into 3 equal parts.
Roll the first part into 12" wide and about twice the length of your pan.
Spread the dough with chocolate filling, leaving an uncoated band in the center and about 1"-2" from the bottom edge.
Sprinkle with chopped nuts or cake crumbs.
Starting with the edges furthest from you roll the dough towards you into a tight log and seal the bottom.
Fold the dough into half and twist it 3-4 times into a spiral.
Place the loaf into your prepared pan, brush with egg wash and sprinkle with streusel.
Let rise for about 2-3 hours.
Preheat oven to 350F and bake for 45-50 minutes, until the loaf is a rich brown color, and a thermometer reads 190-200F when inserted to the center of the cakes.
Remove from oven and let cool for about 10-15 minutes before removing from pan and slicing.