Crunchy hazelnut praline

1. Place all ingredients in a bowl and mix with a wooden spoon until smooth.
2. Spread the mixture on a baking sheet covered with parchment paper to a thickness of about 5 mm in the shape of a large rectangle
3. Place in the fridge to firm up the praline crisp then cut with a large knife to obtain a rectangle of about 4 inch / 10 cm wide by 12 inch / 30 cm long.

Whipped hazelnut Praline ganache

1. Chop the white chocolate finely with a knife and place it in a container.
2. Place half of the heavy cream with the praline paste in a saucepan and bring to a boil.
3. Pour it all at once over the white chocolate and mix with a wooden spoon or spatula until the mixture is liquid and smooth without lumps.
4. Add the other half of the heavy cream and mix, cover with cling film and place in the fridge for one night (or 1 hour in the freezer)
5. Before assembling, place the cold ganache in the bowl of a mixer and beat on medium speed for about 3 minutes until you have a smooth ganache.

Viennese chocolate sponge cake

1. In a bowl, mix together the cocoa powder and flour.
2. Preheat the oven to 355°F / 180°C and prepare a baking sheet lined with parchment paper.
3. Separate the egg whites from the yolks and whisk them with an electric whisk until stiff and set aside.
4. In a bowl, whisk the egg yolks with the sugar and vanilla for about 2-3 minutes.
5. Add 1/3 of the stiffly beaten whites and fold in with a spatula.
6. Add the dry ingredients, flour and cocoa through a sieve and fold in gently with a spatula.
7. Finish by adding the remaining egg whites and fold in gently with a spatula.
8. Pour the batter onto your parchment paper-lined baking sheet and spread in an even layer along the length of the sheet.
9. Bake for about 8 to 10 min max and let cool slightly for a few minutes.
10. Gently peel the soft chocolate sponge off the parchment paper and place it on a clean sheet of parchment paper.
11. Trim the edges with a knife to make a straight rectangle and let it cool for a few more minutes.
12. Garnish the inside of the chocolate sponge with a layer of whipped ganache spread over the entire surface and roll the log lengthwise as tightly as possible and place in the refrigerator for 1 hour.
13. Place the log on a dish or baking tray and cover entirely with ganache and decorate with chocolate shavings.