Preheat oven to 200 degrees C
Add milk and vanilla to a pot and heat until the milk is hot but not boiling
In a mixing bowl whisk together the egg yolk, sugar and cornflour until pale and well combined
Slowly stream the milk into the egg mixture while continuously mixing
Return the custard to a pot on the heat and cook until thickened, continuing to whisk for around 3-5 minutes
Set the pastry cream aside in the fridge covered
Cut out 8 squares of pastry and place onto a lined baking tray
Cut 1cm strips of pastry and place on top of each square like a border
Lightly brush the whisked egg over the squares
Bake for 20 minutes or until golden and puffed up
Once the pastry has cooled, press down the centre slightly and pipe generously with the crème pâtissière
Top with sliced raspberries or any other berries of your choice
Dust with icing sugar
