Hazelnut White Chocolate Mousse Cake

Preparation

For the Toasted Hazelnuts

1. Preheat a dry skillet over medium heat, add 296 ml (1 1/4 cups) hazelnuts, stirring to keep from burning, until just lightly browned. Remove from heat. Remove nuts from pan and let cool to room temperature.
2. Set aside 237 grams (1 cup) of toasted hazelnuts.
3. Fit a dry, clean food processor bowl, that is not hot (from the dishwasher) or cold (from the fridge) with a fine shredding disk, (the steel blade can also be used).
4. Add 59ml (1/4 cup) of hazelnuts to food processor. Pulverize to a fine powder. Scrapping the sides and corners of the processor with a chopstick to keep from sticking. Set aside.

For the Hazelnut Cake:

1. Preheat oven to 177°C (350°F). Prepare the batter for the cake mix according to instructions.
2. Add the 59 ml (1/4 cup) of finely ground toasted hazelnuts to the cake batter, stir in gently.
3. Grease a 20 cm (8 inch) cake pan and add batter to nearly full. Bake according to package directions.*
4. Remove from oven when done according to cake box package. Cool in pan on cake rack.
5. The cake will have risen, using a long sharp knife, level cooled cake so the top is flat, disregard cuttings. Remove cake from pan.
6. Place cake in the center of another, larger, 25 cm (10 inch) spring-form pan. Set aside while you prepare the hazelnut paste.

* NOTE: This recipe will make batter for two 8″ cakes, only one will be used, the extra batter may be baked as cupcakes or made as an extra cake and can be frozen for future use.

For the Hazelnut Paste:

1. Place the remaining 237 ml (1 cup) toasted hazelnuts in the same food processor bowl.
2. In a separate bowl combine the brown sugar, cinnamon, and cream or milk.
3. Process the hazelnuts until they resemble sand.
4. Add the brown sugar mixture to the nuts, process until the mixture is smooth and begins to ball together.
5. Using a piece of parchment paper, trace a circle with the 20 cm (8″) pan. Scrape the nut mixture into the circle. Form the paste with your hands into the circle, creating a flat layer.
6. Flip the parchment paper with the hazelnut paste layer on to the top of the cake, carefully peeling the paper away from the paste, creating a new layer to the cake.

For the White Chocolate Mousse:

1. In a double boiler, melt the butter and add the white chocolate. Melt until silky.
2. Remove from the double boiler, cool slightly, then quickly whisk in the 2 eggs, one at a time.
3. In a separate large bowl, combine the heavy cream with the sugar and nutmeg. Whip until the mixture will hold peaks but is not stiff.  Add the white chocolate mixture and gently fold together until blended.
4. Pour the mousse into the pan over the cake & hazelnut paste, making sure to cover the cake and paste layer, including the sides of the cake, filling the pan entirely. Smooth out top.
5. Freeze the cake for 5 hours or preferably overnight.

For the White Chocolate Mirror Glaze (Optional)*:

1. In a double boiler melt the white chocolate. Whisk in the remaining ingredients for the glaze.
2. Set aside for at least 1 hour at room temperature, stirring occasionally to prevent a skin from forming on the surface. Before glazing, the glaze should be cool and the cake should be very cold.
3. Remove the cake from the springform pan by first running a knife around the inside edge of the pan, then removing the side ring. Place the cake on a cooling rack set over a sheet pan with sides.
4. Pour the glaze over the cake, allowing it to fall and evenly cover the top and sides of the cake. Chill the cake until the glaze is set.
5. Garnish with additional nuts or other embellishments as desired. Photo uses rough chopped hazelnuts, pine tree sprigs, and edible gold glitter.
6. The glazed cake should be served at a very cold temperature, either refrigerated or frozen, and refrigerated immediately after serving, in order to preserve its form.

Adapted from: https://chefiso.com/p/white-chocolate-mirror-glaze-recipe/