Trianon Royal
Dacquoise noisette, praliné croustillant, mousse au chocolat
Dacquoise noisette
- 150 g icing sugar
- 135 g hazelnut powder (or almond)
- 150 g egg whites (~5)
- 50 g caster sugar
Praliné croustillant
- 500 g praliné (50% almond/hazelnut)
- 125 g dark couverture chocolate
- 250 g feuilletine (pailleté feuilletine)
Mousse au chocolat noir
- 200 g dark couverture chocolate (Venezuela)
- 50 g whole milk (or cream)
- 250 g whipping cream (35%), whipped
The Trianon is an entremets built entirely on texture contrasts: crunchy dacquoise base, brittle praliné croustillant, and a light chocolate mousse on top. This is the reworked version — a simple chocolate-and-whipped-cream mousse (no pâte à bombe), which is lighter and cleaner than the earlier egg-yolk version. Assemble in a metal frame and set in the fridge.
Method
Dacquoise noisette
- Grind the icing sugar and hazelnut powder together in a food processor for 3 min, then sift. Set aside.
- Whip the egg whites with a pinch of salt on medium speed. When foamy but far from firm, rain in the caster sugar in 3 additions and whip until no sugar crystals remain — but stop before the meringue is stiff, or it won't fold in cleanly.
- Fold in the powder mixture gently with a spatula — do not whisk. Pipe two 22 cm spiral discs onto parchment, starting from the centre.
- Dust the discs with icing sugar twice, 10 min apart. Bake at 170°C for 10–13 min until lightly coloured and the top just cracks under a finger. Cool.
Praliné croustillant
- Gently melt the dark chocolate. Add the praliné and mix to a smooth paste.
- Fold in the feuilletine without crushing it too much.
- Spread immediately over a cooled dacquoise disc in a thin ~5–8 mm layer. Smooth with an offset spatula and refrigerate to set firm.
Feuilletine is crushed crêpes dentelles. Cornflake crumbs are a workable substitute but less delicate.
Mousse au chocolat
- Whip the cream to soft peaks (bec d'oiseau) — never firm.
- Melt the dark chocolate. Warm the milk and stir it into the melted chocolate to a smooth, glossy emulsion.
- Fold a third of the whipped cream into the chocolate to loosen it.
- Fold in the rest of the cream gently with a spatula. Use straight away, while it is still fluid.
Assembly
- Set a 24 cm metal frame on a tray or board. Place the dacquoise + croustillant inside, croustillant facing up.
- Pour the mousse over the top. Smooth carefully with a spatula; run a decorating comb over the surface if you like.
- Refrigerate at least 2–4 hours, ideally overnight, until set.
- Warm the outside of the frame (blowtorch or hot towel) and lift it away vertically. Dust with unsweetened cocoa and decorate as desired.
Background
The Trianon (also called the Royal) is a textbook entremets — it teaches the three fundamental layers of French mousse cakes: biscuit, croustillant, mousse. The dacquoise stays crisp because it is protected from the mousse by the croustillant layer — without it, moisture from the mousse would make the dacquoise soggy within hours.
The reworked mousse is a simple emulsion of melted dark chocolate loosened with warm milk, lightened with softly whipped cream. It is lighter and less rich than a pâte-à-bombe mousse, and much simpler to make. The cream must be whipped only to soft peaks — over-whipped cream makes the mousse dense and grainy.
Chill, don't freeze. A few hours in the fridge (ideally overnight) sets the mousse enough to unmould cleanly with a warm frame, and the dessert is served straight from the fridge rather than tempered from frozen.
Mistakes I've Made
- Mousse too warm when poured. It melts the croustillant and bleeds through. The chocolate emulsion should be barely warm and the mousse just made when poured.
- Croustillant too thick. Impossible to slice cleanly — the feuilletine shatters and the layers separate. Spread thin (~5–8 mm).
- Whipping cream to firm peaks. The mousse turns dense and grainy. Soft peaks (bec d'oiseau) only — the cream should still flow.
- Meringue whipped too stiff. A stiff dacquoise meringue won't fold into the nut powder without deflating. Stop as soon as the sugar has dissolved.
Sources
- Trianon / Royal —
- Dacquoise —
- Trianon chocolat —