In a bowl, mix the egg with the powdered sugar. Add chestnut flour, and melted butter. Mix well. In another bowl, beat egg whites with powdered sugar. Gently fold the egg whites into the mixture using a pastry blender. Pour the cookie dough onto a baking tray lined with baking paper. Bake for 8-10 min at 180°C. Remove from the oven and leave to cool before cutting out with a round cookie cutter to fit the diameter of your silicone mould opening.
Poach the chestnut cream over the cookies and place in the freezer. For the chestnut cream, you can make your own using vacuum-packed or jarred chestnuts, or use ready-made cream.
Melt the white chocolate in the microwave. Add crumbled crêpes dentelles and chestnut cream…. Mix gently. Roll out between two sheets of baking paper and place in the freezer. Remove from the freezer and cut out using the same cookie cutter used to cut the chestnut cookie. Keep in the freezer until ready to assemble.
Place the gelatine leaves in a large bowl of cold water. In a saucepan, heat the 50g of cream and the chestnut cream. Mix well. Remove from heat and add the wrung-out, softened gelatine. Set aside. Whip the chilled cream with an electric mixer. Add the chilled cream to the previous mixture and mix gently.
Assembly
Fill Montblanc silikomart mould with chestnut mousse, add chestnut cookie covered with chestnut cream, cream side in. Top with chestnut mousse and finish with chestnut cream crumble. Place in the freezer overnight.
Mix all the ingredients, wrap and chill in the fridge. Roll out with a rolling pin and cut out with a cookie cutter. Place in the freezer for a few minutes while you preheat your oven to 180°C. Place your dough on a baking sheet between two micro-perforated baking mats. Bake for around ten minutes. Leave to cool.
The next day, turn out the frozen entremets and immediately apply the brown velvet spray. Place the entremet on the sweet cookie and chill until defrosted.