1) Combine all of the dough ingredients, just till everything is moistened. Cover the bowl, and let the dough rest for 20 minutes. Then mix/knead it till it's soft and smooth.
2) Let the dough rise till doubled, 1 to 1 ½ hours.
3) Gently deflate the dough, and divide it in half. Set the pieces aside, covered, while you make the filling.
4) To make the filling: Combine the sugar, cinnamon, cocoa, and espresso. Stir in the melted butter. The mixture will look grainy and oily; that's OK.
5) Shape each half of the dough into a 9" x 18", ¼"-thick rectangle. Don't be fussy about this; 19" or 20" is as good as 18".
6) Smear each piece of the dough with half the filling, coming to within an inch of the edges.
7) Scatter half the chips and nuts over each piece.
8) Starting with a short end, roll each piece gently into a log, sealing the seam and ends. Place each log of dough into a lightly greased 9" x 5" loaf pan.
9) Tent each pan with plastic wrap, and let the loaves rise till they're very puffy and have crowned a good inch over the rim of the pan, 2 to 2 1/2 hours. Towards the end of the rising time, preheat your oven to 300°F.
10) Just before baking, brush each loaf with the egg glaze; pop any air bubbles with a toothpick. Then, cut a deep vertical slash the length of each loaf, cutting through at least 3 layers.
11) Bake the bread for 35 minutes. Tent lightly with foil, and bake for an additional 15 to 25 minutes (for a total of 50 to 60 minutes); the loaves should be a deep-golden brown.
12) To ensure the loaves are baked through, insert an instant-read thermometer into the center of one loaf. It should register at least 190°F.
13) Remove the loaves from the oven, and immediately loosen the edges with a heatproof spatula or table knife. Let the loaves cool for 10 minutes, then turn them out of the pans onto a rack to cool completely.
Yield: 2 loaves.