Sift the flour with the ground hazelnuts and 4 Tbsp of sugar. Beat the egg whites until stiff, adding the rest of sugar quickly in order to obtain a perfectly smooth texture. Finish by folding the sifted dry ingredients with a spatula. Spread onto a baking sheet.
Bake at 375°F until it springs back when lightly touched.
Dark chocolate ganache
Boil the cream and the honey. Pour 1/3 of the cream over the chocolate. Mix rapidly with a spatula to create a smooth and glossy emulsion.
Gradually keep adding the cream to the chocolate while mixing. (Put a damp towel under the bowl to keep in place). Maintain the smooth and glossy texture until all cream is incorporated.
Pour 1/3 of the ganache into a ring mold or cake pan.
Top with a circle of the biscuit. Pour an additional 1/3 of ganache over the top and place another biscuit circle on top. Cover with the remaining ganache and finish with the last biscuit circle. Freeze over night, unmold and turn over so the ganache layer is on top. If you have used a cake pan instead of a ring, you will need to slightly warm the bottom to remove it, then turn it over. Decorate with additional ganache. Leave to defrost for a minimum of 6 hours in the refrigerator.