For the choux pastry, bring the water with salt and butter to a boil in a saucepan. Remove from the heat and pour in the flour all at once.
Put back on the stove and stir until a white skin has formed on the bottom of the pot. Transfer the dough to a mixing bowl and let cool. It should be warm to the touch.
First, beat 1 egg and stir it into the dough with the dough hook of a mixer on high speed. Beat the remaining eggs as well and stir them in.
Fill the dough into a piping bag with a large star-shaped nozzle and pipe about 4-5 cm wide doughnuts onto a baking tray lined with baking paper. Leave enough space in between.
Bake the doughnuts in a preheated oven at 200 °C for about 30 minutes. Remove from the baking tray and immediately cut off a lid with scissors, then leave to cool.
Whip the cream, beat in the sugar, vanilla sugar and cream stiffener. Pour into a piping bag, fill the doughnuts with it, put the lid on and place a dollop of whipped cream on top.
Finish with a pineapple chunk. .