Filling : Mix warm water and FiberCreme until well combined. Add powdered sugar and vanilla powder while stirring continuously until smooth. Add the whole egg and egg yolks, stir until everything is well mixed and dissolved. Strain the mixture and refrigerate for 30–45 minutes.
Pastry Shells : Prepare the instant puff pastry sheets, lightly dust the surface with all-purpose flour, and even it out. Cut the pastry using an egg tart mold (using the wider diameter side). Shape and press the pastry into the molds. Repeat until all pastry is used. Set aside.
Preheat the oven to 210°C (410°F) for 10–15 minutes.
Pour the filling into the pastry molds until full, and bake for 20–25 minutes or until cooked through.
Let cool, remove from the molds, and serve.