I used a Kitchen Aid, but you can use your hands too. Warm the milk up in a small pot until lukewarm. Stir in the yeast and set aside.
Mix the salt and flour. Add the sugar, olive oil, egg yolk and butter. Slowly add the milk mixture and knead until it forms a dough ball. Put the dough in a bowl and cover with a clean towel or plastic wrap. Set aside in a warm, non-draft area for about 30 minutes.
Warm up the oven at 325 F (160 C). Grease a shallow pie pan and dust with some flour. Set aside.
In a pot bring the 500 ml of the milk and sugar to a boil. Add the vanilla sugar sachets or extract.
In another bowl mix the rest of the milk with the egg yolks and the flour.
Add a few spoons from the boiling milk into the bowl of egg mixture. Mix and add slowly to the rest of the pot with milk. Keep stirring until the custard thickens. It should be a little thicker than pudding (mine was a little too soft and runny).
Pour the custrad in a bowl, cover it with plastic, so no skin will form when it cools down. Set aside.
Mix the flour, sugar and salt in a bowl. Cut in small pieces of butter and rub until small crumbs form.
Roll out the dough on a flour dusted surface. It should be a little bigger than your pie pan. Cut off excess of the dough. Poke holes in the crust with a fork.
Slowly pour the custard onto the crust and crumble the crumble on top.
Put the pie in the oven for 25 minutes or until the crumbs start to slightly brown.
Cool off and enjoy!
The recipe I used was too sweet for my taste, so I adjusted the amount of sugar in this “vlaai”.
Also the custard wasn’t thick enough. I was hoping it would set after the “vlaai” was baked. It was still a little runny. Next time I keep it on the stove a little longer!
In case you do have custard powder and you do not want to make the Banketbakkersroom, you can make it like this:
1 liter of milk
85 grams custard powder
150 grams sugar
2 egg yolks
Mix custard powder and sugar. Add a little bit milk and the egg yolk. Mix together. Bring the leftover milk to a boil in a pan. Add a little bit of hot milk in custard/egg yolk mixture, mix together and then add it all to the pan with hot milk. Keep your eyes on the pan and keep stirring the mixture till it's boiling again. Take the pan off the heat right away and pour it out on a cold kitchen bench to cool down a bit. Then put it in a container and set it in the fridge to cool down completely.