1. Preheat the oven to 150°C (130°C fan-forced) and line a baking tray with parchment paper.
2. Whisk egg whites in a clean, dry bowl until soft peaks form.
3. Gradually add sugar, beating until the mixture is thick and glossy.
4. Fold in cornflour, vinegar, and vanilla extract.
5. Spread the meringue mixture onto the prepared baking tray, smoothing it into an even layer.
6. Sprinkle flaked almonds on top of the meringue.
7. Bake for 30-35 minutes until the meringue is lightly golden and crisp on the outside.
8. While the meringue bakes, prepare the sour cherry compote by cooking cherries, sugar, and lemon juice in a saucepan until thickened.
9. Let the compote cool completely.
10. Whip the cream with icing sugar until soft peaks form.
11. Gently fold in yogurt and optional liqueur.
12. Once baked, allow the meringue to cool slightly before flipping it onto a sheet of parchment paper.
13. Carefully peel off the baking paper from the meringue.
14. Spread the whipped cream mixture evenly over the cooled meringue.
15. Spoon the cherry compote over the cream layer.
16. Using the parchment paper to help, gently roll the meringue into a roulade.
17. Transfer the roulade to a serving platter, seam side down.
18. Spread additional whipped cream on top of the roulade.
19. Garnish with fresh raspberries and extra flaked almonds.
20. Serve the roulade immediately or refrigerate until ready to serve.