Using a whisk, Combine flour and sugar,
Add: 4 egg yolks and about 40mL of the milk, whisk until combined. Add remaining milk and scrape in vanilla pod.
Stir over medium heat, till it thickens (Often scraping the bottom). When it's thick and bubbles start to blob up, remove from heat.
Stir in 30g real butter
Allow to cool with plastic wrap on surface to prevent a "skin". Refrigerate until cold.
If you like, fold a cup of whipped fresh cream into the cold custard cream.
Custard
Melt Butter in a small saucepan, Stir in Sugar, then flour.
Top Crust Dough
Place butter, salt and water in a large saucepan over high heat.
When butter is melted and it starts to boil, remove from heat and Immediately tip in flour all at once, and beat into a firm dough with wooden spoon.
In a separate bowl, lightly whisk 5 eggs. Add approximately one egg to the dough at a time, beating well in between with a wooden spoon.
Spoon into a Piping bag and Pipe directly downward onto paper-lined tray. If you like, use chopsticks or fingers to pull pastry upwards on the sides.
Place thin discs of Top Crust Dough (from step 1) on top of each.
Immediately bake in a very hot oven 410-430 degrees F, 25-30min until well puffed and browned then down to 210 degrees F for 40 min or more to dry.
