Mix together the flour, icing sugar, add the fat and egg.
Whisk the salkali in the milk and add to the flour mixture. When the dough is mixed, divide into 6 dumplings.
Roll the dough balls into a rectangle. Bake in a preheated oven at 180°C for about 8-10 minutes.
To prepare the cream: start heating the milk. When the milk is almost boiling, add a couple of ladles to the dry ingredients and mix until smooth. Then pour the cocoa mixture into the milk on the stove and cook, stirring constantly, until thick. When thick, add the butter and leave to cool.
When the cream has cooled to lukewarm, divide it equally between the 6 sheets and spread the cream evenly over the sheets and assemble the sheets. When ready, cover with cellophane and kitchen towel and leave to soften in a cool place for 1 day. When softened sprinkle with icing sugar and serve.