Prepare the dough: Preheat the oven to 200°C (400°F). Roll out the buttered dough and cut into rectangles (e.g. 8-10 cm). Place them on a baking sheet lined with baking paper.
Brush the top with egg, prick with a fork and bake for approx. 15-18 minutes, until golden brown and well risen. Leave to cool.
To make the cream: Bring the milk and the chopped vanilla bean (or extract) to the boil in a saucepan. In a separate bowl, beat the egg yolks with the sugar until light and fluffy, then add the flour.
When the milk has come to the boil, slowly pour it into the egg yolks, stirring constantly. Then return the mixture to the saucepan and cook over low heat until thickened (about 3-5 minutes).
Remove from the heat, add the butter and mix well. Leave to cool and cover the top of the cream with cling film to prevent a skin from forming.
To assemble the dessert: Cut the baked cake layers in half. Spread a generous amount of vanilla cream on the bottom, then cover the top with the cake layers.
Sprinkle with icing sugar before serving.
Serving and storage tips:
This dessert is best fresh, but can also be made a few hours in advance and stored in the refrigerator.
Serve cold, with seasonal fruits or jam.
The vanilla cream can be stored separately in the refrigerator for up to 2 days.
Variations:
With fruit: Add strawberry, raspberry or blueberry slices to the cream.
Chocolate version: Add 2 pieces of dark chocolate to the prepared cream and stir until melted.
With almonds: Sprinkle the top of the cake with almond shavings before baking.
