Preheat an oven to 190 Celsius degrees (170 for fan ovens).

Line a 25 cm x 35 cm (or similar) baking tin with baking paper.

Whisk the egg whites till stiff; continue whisking and add 1 tbsp of sugar, beat for 10-20 seconds more and add another 1 tbsp of sugar, continue until you have used all the sugar.

Gently stir in the almond extract, vinegar and ground almonds.

Spread in the prepared tin, sprinkle with the flaked almonds, put to the oven and bake for 30 minutes till golden and firm.

Remove from the oven, cover with a sheet of baking paper and a damp tea towel.

Whip the cream till stiff; stir in the chestnut puree.

Remove the tea towel from the top of the meringue but keep the baking paper. Carefully flip the meringue upside down so the top with the flaked almonds is now on the bottom on the paper.

Gently peel off the paper and spread the chestnut filling on top.

Roll the roulade carefully, use the paper to help you.