Paris-Brest with Hazelnut Praline Cream

1. Make the choux pastry:
   In a medium saucepan, bring the water, milk, butter, salt, and sugar to a boil over medium heat. Once the butter has fully melted and the mixture starts bubbling, remove from the heat briefly.
2. Add the flour:
   Pour in all the flour at once and stir vigorously with a wooden spoon. Continue mixing until the dough pulls away from the sides and forms a smooth ball.
3. Dry the dough:
   Return the pan to medium heat and cook the dough for about 2 minutes, stirring constantly to dry it out slightly. A thin film should form at the bottom of the pan.
4. Add the eggs:
   Off the heat, incorporate the eggs one at a time, mixing thoroughly after each addition. The dough should become smooth, glossy, and slightly elastic—soft enough to pipe but still hold its shape.
5. Shape and top the choux:
   Pipe a ring (or individual circles) of choux pastry onto a baking sheet lined with parchment paper. Sprinkle with roughly chopped hazelnuts to create a crunchy topping that will toast during baking.
6. Bake:
   Preheat the oven to 180°C. Bake for 35 minutes without opening the door, allowing the pastry to puff up and turn golden brown. Once baked, turn off the oven, crack the door open, and let the pastry cool inside to prevent it from collapsing.
7. Start the pastry cream:
   Heat the milk in a saucepan until just below boiling point. In a separate bowl, whisk the egg yolks with the sugar and cornstarch until pale and smooth.
8. Cook the cream:
   Gradually pour the hot milk over the egg mixture, whisking continuously. Return everything to the pan and cook over low heat, stirring constantly, until the mixture thickens into a smooth, rich pastry cream.
9. Add the praline:
   Off the heat, stir in the hazelnut praline paste until fully incorporated. Let the cream cool completely, then add the softened butter and whisk to a silky, spreadable consistency. Chill before using.
10. Make the whipped cream:
    In a cold bowl, whip the chilled heavy cream with the icing sugar until firm peaks form. Be careful not to overwhip—it should remain light and airy.
11. Assemble the Paris-Brest:
    Once the choux ring is fully cooled, carefully slice it in half horizontally using a serrated knife. Pipe or spoon a generous layer of the praline cream onto the bottom half. Pipe a layer of whipped cream on top of the praline cream.
12. Finish and garnish:
    Sprinkle with additional chopped hazelnuts and dust with icing sugar. Gently place the top half of the pastry back on and press lightly to secure without flattening the filling. Chill before serving.

Tips & Variations

• Make-ahead tip: Prepare the praline cream the day before and store it in the refrigerator for easier piping and better texture.
• Swap suggestion: For a milder flavour, substitute hazelnut praline with almond praline in the same quantity.
• Extra crispiness tip: After baking, let the pastry cool slowly in the oven with the door slightly ajar to maintain a crisp shell.