Bake the sponge in advance if you need to prepare ahead. To keep it moist, wet some wax paper, wring it out, wrap it around the cooled sponge and put the cake in a plastic bag. This will keep it fresh for a day or so until you are ready to roll and decorate it.

Ingredients

Preheat the oven to 400 degrees F

For the sponge:
4 extra-large eggs at room temperature
1/2 cup superfine sugar
1/2 cup self-rising flour
1/4 cup cocoa powder

For the filling:
8 oz. can unsweetened chestnut puree
1 Tbsp. coffee extract
1/4 cup superfine sugar
1/2 cup plus 2 Tbsp. heavy cream, stiffly whipped
2 Tbsp. brandy

For the fudge icing:
4 Tbsp. melted butter
3 Tbsp. cocoa powder
about 3 Tbsp. milk
1 cup confectioners' sugar, sifted

Directions

1. Grease and line a jelly roll pan. Whisk together eggs and sugar in a large bowl until the mix is light, then sift in the flour and cocoa and fold them into the mixture.

2. Turn the mix into the prepared pan and spread it evenly. Bake in a preheated oven for 10 minutes. Turn the cake out onto wax paper and let cool.

3. To make the filling, put the puree in a bowl and beat in the coffee extract and sugar until smooth. Fold in the cream and brandy. Spread the filling over the cooled sponge.

4. Peel off the paper as you roll the sponge up. Mix the butter and cocoa, add the milk and confectioners' sugar, beat until smooth. Decorate the cake with icing to look like a log.