This modern layered slice was invented by a celebrated French pastry chef Stephane Glacier. I learned how to make it at university, and let me tell you, even just reading what the components are, my mouth was drooling! There are 5 distinct layers: crispy wafer bottom, chewy hazelnut dacquoise, creamy chocolate cremeux, light milk chocolate chantilly, and a final layer of tempered chocolate on top. It is a slightly technical recipe, but read it carefully and follow the steps, and I’m sure you’ll master it in no time. The original recipe also requires some hard to get ingredients, all of them which you can get online, however I have provided more accessible alternatives as well. Finally, make sure you have space in your fridge for this one, because there is a lot of chilling and setting (ideally set your fridge to the coldest setting). If you have a lot of freezer space that would be even more useful and maybe even quicker.
For the dacquoise:
- 70 ground hazelnuts
- 100 g icing sugar
- 90 g egg whites (about 3 large)
- 40 g caster sugar
- 3 g salt
- 40 g chopped hazelnuts
For the crispy bottom layer:
- 100 g Nutella
- 100 g hazelnut praline paste or hazelnut butter (you can leave this out and substitute for more Nutella)
- 50 g milk chocolate, preferably milk chocolate chips
- 30 g feulletine (this can be found online, or you can substitute with crushed wafers, just crush them finely and toast in the oven at 180 C for 10 minutes)
- 15 g unsalted butter, softened
For the milk chocolate chantilly:
- 300 g double cream / whipping cream
- 50 g whole milk
- 170 g milk chocolate
For the dark chocolate cremeux:
- 125 g dark chocolate
- 55 g whole milk
- 125 g double cream / whipping cream
- 1 tsp vanilla extract, or 1/4 vanilla bean pod
- 45 g egg yolk (about 2.5 egg yolks)
- 25 g caster sugar
- 12 g unsalted butter
- 5 g salt
- First prepare the dacquoise. Preheat the oven to 170 / 160 C fan, and line a large rectangular baking tray with parchment paper. Mix together the ground hazelnuts and icing sugar, set aside. In a large metal or glass bowl place the egg whites and salt. With a hand mixer, or on a stand mixer, start whipping the egg whites until foamy. Once it begins to become fluffy and white start adding the caster sugar little by little. After all the sugar is added, continue whipping until stiff peaks form and when you rub your fingers in the meringue you don’t feel any sugar crystals. Slowly tip in the ground hazelnut mixture and using a large rubber spatula, fold the mixture slowly and gently, trying to keep as much air as possible. Finally add in the chopped hazelnuts and fold them in too. With your fingers, ‘wipe’ some of the meringue mixture into the corners of the baking tray, underneath the parchment paper; this will make sure the paper doesn’t slide around. Tip the rest of the mixture onto the parchment and use a rubber spatula to spread it out quite thinly, almost to just 5 millimetres. Bake for 20-30 minutes until the dacquoise is slightly golden brown and fully set. Let cool at room temperature while you make the crispy bottom.
- Next up is the crispy bottom. If using wafers, crush and toast them first. Place the milk chocolate chips into a microwave safe bowl and put in the microwave for 1 minute. Stir until fully melted. If there are any large chunks that haven’t melted, zap it for 10 second intervals. Mix the melted chocolate with the feulletine/wafers. Add in the salt, Nutella, praline and butter and thoroughly mix until combined. This mix should be fairly thick, but still spreadable. Once the dacquoise has fully cooled, spread the crispy Nutella mix over it and make sure it’s in an even, fully flat layer. Place in a very cold fridge, or ideally a freezer for a few hours until it fully sets.
- While the bottom is cooling, make the dark chocolate cremeux. In a saucepan, put together the milk, cream and vanilla, and gently heat it up over a low heat. While the mixture is coming to a simmer, whisk together the egg yolks, sugar and salt. Once simmering, take the milk mixture off the heat and pour slowly into the egg yolks while constantly whisking. When you’ve tempered the yolks, place the whole mix back into the saucepan and using a wooden spoon or a spatula stir and cook continuously until thickened. The mixture should either coat the back of the spoon or read 83 C on a thermometer. Once cooked, mix in the chocolate and butter until melted and combined.
- Take the dacquoise out the freezer and invert onto another piece of parchment paper, so the crispy Nutella layer is on the bottom. Pour the slightly cooled cremeux over the dacquoise layer and spread out evenly. Again place in the fridge/freezer for a few hours until fully set, ideally overnight.
- For the milk chocolate chantilly, heat up the milk with 150 g of cream and pour over the chocolate. Mix until a thick ganache is formed. Slowly pour in the rest of the cream into the ganache until a thin emulsified chocolate cream is formed. Cover it with plastic wrap touching the surface and place in the fridge overnight.
- The next morning, cut up the base in desired shape/size. Try and keep everything cold, so go back and forth into the fridge as needed. Using a mixer, whip the cold chocolate cream into a soft chantilly. Be careful not to over whip, otherwise it’ll go too stiff and grainy. Using a desired piping tip, pipe on top of each base in an even layer.
- Optional, temper some chocolate and create decorations of choice for the top of the bars. Chill again and serve cold. Enjoy!