Meringue and nut cake "Dacquoise"

Ingredients:

Dacquoise cake

• 1 cup toasted and peeled hazelnuts
• 1 and 1/4 cups sugar
• Whites of 6 large eggs
• 1 teaspoon cream of tartar

Caramel mousse

• 6 tbsp water, divided
• 3/4 cup sugar, divided
• 1 tbsp white corn syrup
• 1 tsp. powdered gelatin
• 2 large eggs plus 2 large egg yolks
• 1 cup whipping cream
• Powdered sugar for sprinkling

Preparation:

1. Preheat oven to 110°C. Use a marker to draw 3 circles, each 15 cm in diameter, on parchment paper. Turn the sheets of paper over so the drawings are facing down and place them on baking sheets.
2. Grind hazelnuts with 1/4 cup sugar until finely ground.
   
   Beat the egg whites and cream of tartar on low speed, gradually increasing the speed until the whites are foamy, then slowly add the remaining 1 cup of sugar. Increase the speed to high and continue beating until stiff peaks form. Fold in the ground hazelnuts.
3. Place the meringue in a piping bag fitted with a large, plain tip. Pipe it in a spiral pattern inside the circles drawn on the parchment paper, filling them completely.
4. Bake the meringues for about 1 hour and 30 minutes, until they're firm after cooling. If they're still soft, you can return them to the oven to dry them out (baking time may vary depending on temperature and humidity). The meringues will expand as they bake, reaching about 20 cm in diameter, and it's okay if they darken slightly. The meringues can be baked up to 2 days in advance and stored in an airtight container, and the cake can be assembled a day before serving..
5. Caramel mousse.
   
   Pour 4 tablespoons of water into a small saucepan, then add 0.5 cups of sugar and corn syrup. Bring the sugar to a full boil without stirring, and continue cooking until the caramel turns a light amber color, occasionally brushing the sides of the pan with water. Remove from heat and let cool slightly (it will continue to darken slightly as it cools).
6. Soak the gelatin in the remaining 2 tablespoons of cool water. In a metal bowl, whisk the eggs, yolks, and the remaining 1/4 cup of sugar. Place the bowl over a saucepan of simmering water, whisking vigorously until the mixture doubles in volume and forms a ribbon when lifted. Remove the bowl from the water bath and whisk in the gelatin, then fold in the caramel, being careful not to spill any onto the whisk. Cool to room temperature.
7. Whip the cream until soft peaks form and whisk into the cooled caramel mixture. Refrigerate for at least 2 hours before assembling, or until the mousse has set.
8. Place the first meringue on a plate. Place the mousse in a piping bag fitted with a large plain tip and pipe half of the mousse onto the cake. Place the second meringue on top and pipe the remaining mousse onto it, then cover with the remaining meringue. Refrigerate the cake until ready to serve, then dust with powdered sugar before serving.