Layered lemon chestnut entremet cake

Pass hot roasted or steamed chestnuts through a food mill. Add simple syrup, water, rum and chestnut cream, heat, and add softened gelatine.

Pass the chestnut mixture through a sieve and shape it an inch (2.5 cm) smaller in diameter than the cake ring. Freeze, demould and keep frozen.

Toast the walnuts. Cook honey, water and butter to a dark amber caramel, toss in the toasted walnuts and keep on the heat until each nut is coated; cool on a silicone baking mat.

In a food processor, mix room temperature chestnut cream, rum and softened butter. Add the eggs, flour and baking powder; once homogenized add chestnut chunks and pulse a few more times.

Fill the prepared mold and bake at 350F, 180C, for about 25 minutes.

For the lemon gel, heat lemon juice, water and vanilla in a saucepan, add the sugar and agar-agar mixture, bring to a boil and cook 2 minutes. Cool and chill until completely set.

Smooth the gel with an immersion blender, add the preserved lemon peel, shape to the theme and freeze.

For the mousse (ganache montée), boil the first half of the heavy cream with vanilla, add to the white chocolate, then the softened gelatin, chestnut cream and the remaining chilled heavy cream. Mix and refrigerate overnight.

Cut the sponge into three slices, the bottom one thicker. Beat the chilled ganache montée to soft peaks without over-whipping, or it will not spread and leave air pockets.

Place the thick sponge in a cake ring, pipe mousse around and coat the edges with the back of a spoon so no gaps remain. Add the frozen cremeux, a sponge and the lemon gel; top with mousse, level with an offset spatula and freeze overnight.

variation: build a second cake upside down in a silicone mold: mousse, lemon gel, cremeux and one sponge. Freeze overnight and demould.

Glue three caramelized walnut halves on top with leftover mousse and freeze. Optionally pipe a chocolate lace from tempered dark chocolate in parchment cones.

Spray the frozen cake with a warm one-to-one mixture of cocoa butter and chocolate for a velvet finish.