Line an oven tray with a silicone mat. Roast the hazelnuts in the oven for 15 minutes at 165°C.
Gently melt the sugar in a saucepan. You can stir it, but if you keep the heat low, it will eventually melt completely.
Once the caramel is amber and starting to smoke, pour it over the roasted hazelnuts. Leave to harden completely (1h minimum) before breaking into pieces. Set aside.
A few hours in advance, line a silicone mold for mini half-spheres with praline and place in the freezer. You can also skip this step and place a teaspoon of praline directly in the center of your mold.
Preheat your oven to 180°C.
Start by buttering a dozen or so metal molds.
Melt your butter and chocolate in a bain-marie (or gently in the microwave). Whisk the eggs and sugar in a large bowl until they form a smooth, airy mousse.
Add the chocolate/butter mixture to the egg/sugar mixture and stir gently with a pastry blender. Finish by stirring in the sifted flour.
Fill your molds 2/3 full, then place a large teaspoon of praline paste in the middle or one of your frozen praline half-spheres, then cover with a little paste.
Bake in a preheated oven at 180°C for 9 minutes.
Once the fondants are cooked, turn them out onto a plate and sprinkle with hazelnut flakes.
Enjoy!
