For the choux pastry, bring 125 ml water to the boil with salt and butter. Mix in the flour briskly at the beginning with a whisk. Stir on top with a wooden spoon until the amount separates as a dumpling from the bottom of the pot and a white coating becomes visible (this takes 1-2 min). Allow the dough to cool for 5 minutes. Then, using the dough hooks of the mixer, add the eggs one at a time and mix until a tough but smooth dough forms. One egg must be fully incorporated before adding the next.
2. transfer batter to a piping bag fitted with a medium nozzle. Pipe about 30 hazelnut-sized dots onto a baking sheet lined with parchment paper, spacing 3 inches apart. Press dough tips a tiny bit flat with a damp finger. Bake in the heated oven on the middle shelf at 200 °C (gas 2, convection oven 15-20 min at 200) in 25-half hour until golden brown. Remove from the stove and cool.
For the filling, soak the gelatine in cold water. Boil 150 ml whipping cream with the sugar and vanilla pulp. Quickly stir the vanilla milk with the egg yolks in a whisking kettle and beat over a hot water bath for 3-5 minutes until creamy and thick. Immediately strain through a fine kitchen sieve into a bowl. Squeeze gelatine well and let it melt in the warm vanilla cream. Stir well and cool on ice until the cream begins to gelatinize slightly. In the meantime, stir a few times.
Whip the remaining whipped cream until stiff.