Put the egg whites into a clean mixer with the cream of tartar, and whip until they are a dense foam

While the mixer is running on medium speed, add the vanilla extract then the caster sugar a tablespoon at a time.  

Once it is all added, turn the speed up and continue to mix until the mixture is thick and glossy, and no grains of sugar remain (rub a bit of meringue between thumb and forefinger; it should feel completely smooth)

Pre-heat the oven to 140°C / 280°F / Gas Mark 1

Place the meringue into a piping bag. Line a baking tray with greaseproof paper or a silicone baking mat, and starting in the centre, pipe in an ever widening circle until you have one large disk of meringe. If you have mixture remaining, do the same again on another baking tray 

Bake the meringue for 30 minutes, then drop the temperature to 100°C / 210°F / Gas Mark ¼ and bake for a further 60 minutes. Leave the meringue in the oven with the door slightly ajar, for another couple of hours to dry out. 

Meanwhile, cut your cherries into quarters, and set to one side

Whip the cream until stiff peaks form. If using the syrup, stir this into the cream now. 

To assemble just before serving, add the cherries to the cream and stir through. Then add the meringue, broken into smallish pieces, and stir together. Serve in chilled dishes.