Prepare Choux Pastry: Make choux pastry using water, butter, flour, salt, sugar, and eggs as per standard method.
Pipe the Dough: Transfer the dough to a piping bag and pipe small rounds onto a baking sheet lined with parchment paper.
Bake: Bake in a preheated oven at 200°C (390°F) for 20–25 minutes, then reduce to 180°C (355°F) for 10–15 minutes until golden and puffed. Do not open the oven during baking.
Cool: Remove from oven and let the puffs cool completely on a wire rack.
Prepare Filling: Whip heavy cream with sugar until stiff peaks form, or prepare custard or pastry cream.
Fill the Puffs: Slice the cooled puffs horizontally or make a small hole and pipe the cream filling inside.
Optional Topping: Dust with powdered sugar or drizzle with chocolate ganache for extra flavor.