Place the water, oil, yeast, salt, and sugar in a very large bowl (or bucket). Stir it a few times. Add the flour, cocoa powder and chocolate chips. Mix until there are no lumps of dry flour. Cover the bowl loosely. Leave the mixture to rest for 2 hours at room temperature.
Remove the dough from the bowl and grab enough dough to form a ball the size of a small peach and place it on a baking sheet. Repeat with the rest of the dough. Loosely cover the dough balls with plastic wrap and leave them to rise for about 1 hour and 40 minutes.
Position an oven rack in the middle of the oven. Preheat oven to 350°F. Brush the rolls with the egg wash and then bake them for about 20 minutes.
Remove the rolls from the pan to cool completely before serving.
The nutrition information provided are only estimates based on an online nutritional calculator. This is not a comprehensive list of all the nutrients in the recipe (i.e., does not include vitamins, cholesterol, etc). I am not a certified nutritionist. Please consult a nutritionist or doctor for accurate information and any dietary restrictions and concerns you may have.