In a saucepan, combine water, butter, salt, and sugar over medium heat. Once bubbles form at the edges, remove from heat.

Add sifted flour to the saucepan and mix thoroughly. Cook over medium heat until the dough forms a thin film on the bottom of the pan and no longer sticks.

Transfer the dough to a bowl and let it cool for 2 minutes. Gradually add eggs, mixing until the dough becomes glossy. Repeat this process 3 more times.

Pipe the dough into 5–6cm diameter rounds on a baking sheet. Spray the surface with water and bake at 200°C for 20 minutes, then reduce to 180°C and bake for another 20 minutes.

Heat milk with vanilla bean in the microwave for 1 minute.

Whisk egg yolks with sugar until creamy, then add sifted flour and mix well.

Combine the egg yolk mixture with the warm milk and microwave for 1 minute. Stir gently, then microwave for another 40 seconds.

Cover the custard cream with cling wrap and refrigerate until chilled.

Whip heavy cream with sugar until stiff peaks form. Fold the whipped cream into the chilled custard cream.