Butter the bread slices, sprinkle with cinnamon and cut into triangles. Whisk the sugar and eggs in a bowl. Gently warm the milk with the coffee powder and half of the chocolate. Mix well with the whisk and pour over the eggs. Mix everything well.
Place the pieces of bread in a greased baking dish and pour the pudding cream over them. Let it steep for at least 30 minutes.
Bake the form in a water bath in a preheated oven at 180 ° C for about 1 1/4 - 1 1/2 hours until the pudding is firm. Scatter the remaining chocolate over the pudding about 10 minutes before the end of the cooking time.