Preheat your oven to 160°C (320°F). Line a 35cm x 30cm baking tray with baking paper, ensuring it rises at least 2cm above the edges.

In a large mixing bowl, beat the egg whites until soft peaks form, about 2-3 minutes. Gradually add the castor sugar and beat until glossy and stiff, about 5 minutes. Gently fold in the vanilla, vinegar, cornflour, and sifted cocoa powder.

Spoon the meringue mixture into the prepared baking tray, spreading it evenly to about 1cm thickness. Reduce the oven temperature to 140°C (284°F) and bake for 35 minutes until pale golden brown.

While the meringue cools, whip the double cream and icing sugar until stiff peaks form, about 3 minutes.

Once the meringue is completely cooled, invert it onto a clean kitchen towel sprinkled with icing sugar. Peel off the baking paper gently.

Spread most of the whipped cream over the meringue, layer with cherries, and drizzle with cherry jam.

Using the towel to assist, carefully roll the meringue from one end to the other. Place seam-side down on a platter and slice to serve.