Heat the Butter and Water: In a medium saucepan, combine 50 g of butter, 100 g of water, and a pinch of salt. Bring the mixture to a boil over medium heat, stirring occasionally to ensure the butter melts evenly.

Add the Flour: Once the butter has fully melted and the mixture is boiling, remove the pan from the heat. Immediately add 100 g of flour and stir vigorously with a wooden spoon until the dough comes together and pulls away from the sides of the pan. The dough should be smooth and slightly sticky.

Cool the Dough: Let the dough cool for 5 minutes. It should still be warm but not hot enough to cook the eggs when you add them.

Add the Eggs: Beat the 3 eggs in a separate bowl. Gradually add the beaten eggs to the dough, mixing well after each addition. The dough should become smooth, shiny, and thick enough to hold its shape when piped.

Shape the Choux Pastry: Preheat the oven to 180°C (350°F). Transfer the choux dough to a piping bag fitted with a large round tip. Pipe small mounds (for profiteroles) or long strips (for éclairs) onto a baking tray lined with parchment paper, leaving enough space between each one for expansion.

Bake: Bake the choux pastry in the preheated oven for 25-30 minutes, or until they are puffed up and golden brown. Do not open the oven door during baking, as this could cause them to deflate. Once baked, remove them from the oven and let them cool completely on a wire rack.

Whip the Heavy Cream: In a large mixing bowl, whip 200 g of heavy cream until stiff peaks form. Be careful not to overwhip, as the cream can turn into butter if beaten too long.

Combine Cream Cheese and Sugar: In a separate bowl, beat 180 g of cream cheese with 70 g of powdered sugar, 8 g of vanilla sugar, and 30 g of pistachio paste until smooth and well combined.

Fold in the Whipped Cream: Gently fold the whipped cream into the cream cheese mixture until smooth and fluffy. The result should be a light and creamy pistachio filling with a rich flavor.

Prepare the Pastries: Once the choux pastry has cooled, use a sharp knife to make a small hole at the bottom of each pastry. You can also cut them in half horizontally if you prefer.

Pipe in the Filling: Transfer the pistachio cream to a piping bag fitted with a small round tip. Pipe the cream into each choux pastry until filled.

Optional Decoration: If you like, you can dust the top of the filled pastries with powdered sugar, drizzle them with melted chocolate, or garnish them with crushed pistachios.

Chill: For the best results, chill the filled pastries in the refrigerator for about 30 minutes before serving. This allows the flavors to meld and the filling to set.

Serve: Serve the pastries chilled or at room temperature. These treats are perfect for tea time, dessert, or a special occasion.