Grind the hazelnuts (with skins) in a food processor using a steel blade until fine.

Separate the eggs into yolks and whites.

Melt the chocolate in the microwave in short bursts until smooth.

Whisk the yolks until pale and fluffy. Add the melted chocolate and vanilla, and whisk until combined.

Whip the egg whites with a pinch of salt. Once foam forms, gradually add the sugar and whip to firm, stable peaks.

Gently fold the ground hazelnuts into the yolk mixture.

Lighten the mixture with 2–3 tablespoons of meringue, folding gently with a spatula.

Fold in the remaining meringue in 2–3 additions until smooth and uniform.

Pour the batter into a greased and parchment-lined 28 cm (11") round cake pan.

Bake in a preheated oven at 180°C (350°F) for 40–50 minutes (depending on your oven), until a toothpick comes out slightly moist.

Let the cake base cool completely.

Spread the hazelnuts in a single layer on a plate and microwave for 7 minutes.

Once cooled, rub off the skins and coarsely chop (not too fine).

Heat a large skillet. Add 6 tablespoons sugar and 1 tablespoon water. Allow the sugar to caramelize.

When a light caramel forms and the sugar is fully melted, add the nuts and stir to coat evenly.

Remove from heat and transfer to a parchment-lined tray. Spread out.

Once cooled, crumble and store in an airtight container until serving.

Finely grind the peeled hazelnuts.

Whip the heavy cream to soft peaks. As it thickens, add the vanilla and sugar, and continue whipping to stiff peaks.

In a small bowl, mix the gelatin with water and let bloom for 5 minutes.

Microwave the gelatin for 15–20 seconds until fully melted.

Mix the gelatin thoroughly into the cream until well combined.

Pour the mousse over the cake base, cover, and refrigerate for at least 1 hour until set.

Whip the cream with sugar until stiff peaks form.

Spread evenly over the mousse layer.

Sprinkle with caramelized hazelnuts just before serving.