They can advantageously be made the day before.Pour the nuts onto a baking sheet and roast them for 12 minutes on the second top rack in the oven at 175 degrees Celsius (347 degrees Fahrenheit).

Take them out of the oven and throw them in a colander and let them cool.

Stir the nuts with your hand or a spoon to loosen the shells – there will be some shells that stick partially, but that's okay.

Put the nuts in a food processor along with 200 grams of sugar and chop until the nuts are finely ground.

Get the stand mixer and attach the whisk.

Pour the egg whites into the bowl and whisk them stiff.

Continue whisking and add one tbsp. of sugar at a time until you've used it all – make sure the sugar is whisked well into the egg whites between each spoonful.

Whisk until the meringue is shiny and firm.

Now gently fold the nut/sugar mixture into the meringue until evenly distributed.

Preheat the oven to 130 degrees Celsius (266 degrees Fahrenheit) fan.

Find 3 baking sheets and place a piece of baking paper on each.

Draw a circle with a diameter of 24 cm on each baking paper – use a springform pan or similar as a template.

Evenly distribute the meringue on the sheets (if you have poor judgment like me, place the baking sheet on your scale. There should be approximately 3 x 245 grams). You can also put the meringue in a piping bag without a nozzle and distribute it in a spiral on the baking paper.

Bake the bases in the oven for 1 hour, then turn off the oven and let the bases stand in the oven for an additional 1-2 hours.

Take the bases out and let them cool completely on a rack before removing the baking paper – if the bases are a bit chewy, it's perfect because a fragilité should be a bit chewy!

Put the butter in a stand mixer and whisk it with the paddle attachment until fluffy.

Add 1/3 of your powdered sugar and whisk it into the butter.

Repeat 2 more times until you have used it all and then whisk for 2-3 minutes.

Cut the nougat into cubes and melt it in the microwave or over a water bath.

Add the nougat to the buttercream while whisking.

Now slowly add the espresso while whisking until all of the espresso is incorporated into the buttercream.

Distribute the buttercream on two of the meringue bases and assemble the cake – (you can optionally spread a thin layer on top as well).

Place the cake in the refrigerator for at least 4 hours or until serving.

Decorate the cake with powdered sugar, freeze-dried raspberries, and hazelnuts. You can also make extra buttercream to cover and decorate with!