The calculation is for an 18 cm (7 inch) cake (10 cm | 3.9 inch height).
- Egg whites - 90 g | 3.15 oz
- Sugar - 90 g | 3.15 oz
- Hazelnut flour - 90 g | 3.15 oz
- Powdered sugar - 45 g | 1.60 oz
You can make the hazelnut flour by yourself. Just grind the roasted hazelnuts in a coffee grinder; don’t grind for too long, otherwise the oil will squeeze. Draw three 15 cm (5.9 inch) circles on the back of the parchment, at a distance from each other.
Sift the powdered sugar, and combine it with the hazelnut flour; stir with a whisk. Whip the egg whites with sugar until firm peaks. Pour the hazelnut flour with the powdered sugar into the egg whites, and gently stir with folding movements until smooth, using a silicone spatula.
Transfer the mixture to a pastry bag with a 10 mm (0.4 inch) round nozzle. Spiral the dough onto the prepared parchment. The dough is enough for 3 cakes with a diameter of 15 cm (5.9 inch). Bake it for about 15 minutes at 170C (338F).
- Butter 82.5% - 180 g | 6.35 oz
- Condensed milk - 110 g | 3.90 oz
- Hazelnut praline - 150 g | 5.30 oz
- Egg whites - 200 g | 7.05 oz
- Sugar - 420 g | 14.80 oz
- Glucose syrup - 140 g | 4.95 oz
- Water - 250 g | 8.80 oz
- Agar (-900-) - 15 g | 0.55 oz
You better use the ready-made hazelnut praline (it has a creamy consistency, which is impossible to be reached at home). You can also replace the praline with the hazelnut paste (100-120 g | 3.55 to 4.25 oz).
- First, cook the crème. To do this, whip the butter at the room temperature until fluffy. Pour in the condensed milk (also at room temperature) in a thin stream, while whipping. If the mass has stratified suddenly, then it indicates either a violation of the temperature regime or the low quality of the butter. Such a mass can be slightly warmed up in the microwave with short impulses and whipped again; then it will become homogeneous. Add the praline to the resulting crème, and whip again.
- Wrap the 18 cm (7 inch) ring mold with the acetate foil from the inside, and place it on a substrate. Combine the sugar, the glucose syrup, the water and the agar in a saucepan with a thick bottom. Don’t use a small pot, as the mass will foam a lot. Cook the syrup over a medium heat to 110C (230F), stirring actively with a whisk.
- Meanwhile, whip the egg whites (first at a low mixer speed, and then gradually increase it). The whites have to be whipped into stable foam. If the syrup is not ready yet, then just turn off the mixer (the egg whites mass will be fine). If you use a hand mixer, then first do the whites, and then cook the syrup.
- Remove the finished syrup from the heat, and pour it into the whites in a thin stream, whisking them at a high mixer speed. Keep whipping until the mass cools to about 45C (113F). By this time, it will greatly increase in volume, and become dense and glossy.
NOTE: there will be a lot of egg whites mass, so the volume of the dishes for whipping should be at least 5 liters (8.5 lb).
While whipping, add the crème in a tablespoon. The mass will gradually decrease in volume, and become more liquid. Turn off the mixer, and stir the mass thoroughly once again with a silicone spatula.
Place a biscuit layer in the prepared ring mold, and fill it with 1/3 of the soufflé; carefully put the second biscuit layer on the soufflé, and another 1/3 soufflé on top; the third biscuit layer and again 1/3 soufflé.
Place the cake in the fridge to stabilize completely (for 6 to 8 hours).
For the glaze:
- Dark chocolate 54.5% - 70 g | 2.45 oz
- Butter - 20 g | 0.70 oz
- Cream 33% - 50 g | 1.75 oz
Melt the chocolate and the butter with pulses in the microwave. Add the cream (cold or room temperatured), and stir. If the mix is too thick, heat it a little more, and then pour over the cake.
Place the finished cake in the fridge for 30 to 60 minutes to set the glaze.