To the buttery mixture, add the eggs 1 by 1 while stirring nonstop. Pour 1 tbsp coffee or milk over the chocolate and leave it to cool.
Add half of it to the egg mixture while stirring nonstop. Then stir the mixture with the rest of the milk and the flour mixture in lots.
Pour this mixture into a rectangular, well greased oven dish and put it to bake in a preheated 356°F (180 °C) oven for about 20-25 min.
Cut the baked and cooled cake layer into equal-sized pastries. Heat the remaining chocolate with the chocolate spread and pour the resulting glaze over the pastries.