On a well-floured surface, roll out the dough to form a rectangle, similar in size to a 30 x 38 cm baking sheet. Slather the chocolate spread in an even layer on the surface, leaving a 1.5 cm border of dough.
TIP: I find it helpful place the jar in a hot water bath just long enough to give it enough heat to cause it to melt a little. This makes spreading it much easier.
Brush the surface of the bread with the egg wash. Bake bread for 20 minutes, then increase the temperature to 425°F/200°C and bake until lightly browned, about 5-6 minutes more. Remove from oven and let cool before serving.
NOTE: Be sure to keep a close eye on your bread when you increase the temperature!