Bring the milk with the butter to the boil. In the meantime, mix the sugar, vanilla sugar, flour and salt together. As soon as the milk boils, add the flour-sugar mixture and stir. Let simmer for another 2 minutes, until it is nice and creamy. Remove from heat and let cool down a bit.
Preheat the oven to 225 ° C (top / bottom heat). In the meantime, roll out the puff pastry on a lightly floured work surface with a rolling pin. It should be 34 x 42.5 cm. Then cut out about 20 circles (8 - 8.5 cm in diameter) and place in muffin molds. There should be a border about 1 cm high. Then put the muffin molds on the baking sheet.
Mix the three egg yolks and the whole egg into the milk cream and then use a jug to spread them on the muffin cups. Be careful not to overflow the cream. As soon as the oven is preheated, put in the baking sheet.
Bake for 12 - 15 minutes until the puff pastry has risen, then switch on the grill for another 3 - 5 minutes. The pasteis are ready when they have dark brown spots. Then switch off the oven, open a little and let the pasteis cool down slowly.
The pasteis sink in a bit as they cool down. But don`t worry: they look the same in Portugal! If you want, you can sprinkle cinnamon on top before serving.