Punch down the dough and divide in half. On a lightly floured surface, working with one piece of the dough at a time (keep the other half of the dough covered in plastic wrap), roll out the dough into a 20 x 10-inch rectangle. Spread half of the meringue evenly over the rectangle up to about 1/2-inch from the edges. Sprinkle half of your filling evenly over the meringue (half of the cinnamon-sugar followed by half the chopped nuts and half of the chocolate chips).
Now, roll up the dough jellyroll style, from the long side. Pinch the seam closed to seal. Very carefully transfer the filled log to one of the lined cookie sheets, seam side down. Bring the ends of the log around and seal the ends together, forming a ring, tucking one end into the other and pinching to seal.
Using kitchen scissors or a sharp knife, make cuts along the outside edge at 1-inch intervals. Make them as shallow or as deep as desired but don’t be afraid to cut deep into the ring.
Repeat with the remaining dough, meringue and filling.
Cover the 2 coffee cakes with plastic wrap and allow them to rise again for 45 to 60 minutes.
Preheat the oven to 350°F.
Brush the tops of the coffee cakes with an egg wash:
1 egg beaten with 1 teaspoon water
Bake in the preheated oven for 25 to 30 minutes until risen and golden brown. The dough should sound hollow when tapped.
Serve by cutting into slices and sprinkling with powdered sugar and cocoa powder (optional).
This is best served the same day.