Czech caramel cream puff (Větrník)

1. For the pastry, bring the water to the boil with 100 g of the butter and the salt, tip in 150 g of the flour all at once and beat hard until the dough comes away from the sides of the pan (about 2 minutes). Cool until lukewarm, then work in the eggs one at a time until you have a glossy mixture that slowly slides off the spoon.

2. Pipe 8 round mounds, 7-8 cm across, onto a lined baking tray and bake in an oven preheated to 200 °C for 15 minutes, then at 180 °C for another 20 minutes – don't open the oven meanwhile! Let them cool in the switched-off oven with the door ajar.

3. For the cream, put the scraped seeds and pod of the vanilla into the milk and bring to the boil. Whisk the yolks with 60 g of the sugar and the remaining 30 g of flour until pale, temper with the hot milk, pour back and cook, stirring constantly, into a thick custard; cover and cool.

4. Melt 80 g of the sugar in a frying pan into a golden caramel, take off the heat and carefully add 3 tablespoons of hot water; stir smooth and let cool. Stir half the caramel into the cold custard and beat with the remaining 100 g of soft butter until fluffy. Whip the cream with the remaining 40 g of sugar to stiff peaks.

5. Cut the puffs in half horizontally. Pipe the caramel cream into the bottoms and plenty of whipped cream on top. Spread the rest of the caramel (warm it slightly if it has set) over the lids and place them on top.

6. Chill for at least 1 hour before serving and eat on the same day.

Tip: Větrník (literally "windmill") is the legendary pastry of Czech cake shops: three creams – vanilla, caramel buttercream and whipped cream – in one big choux puff with a caramel glaze; Czech grannies say the lid of a good větrník should "crackle".