Whisk egg whites until quite stiff then add all the other meringue ingredients: vanilla extract, white wine vinegar, cornflour and 100g caster sugar. Gently continue whisking until you can form stiff peaks. Put meringue mixture on a sheet of baking paper. Spread into a slab a couple inches thick - not too flat!
Bake in the preheated oven for about 1hr and 15 minutes. Remove to cool. Break into pieces.
Simmer the clementine pieces with the Bailey's and the 1 tablespoon caster sugar until syrupy, about 5 minutes. Melt the dark chocolate in the microwave. Whip the cream.
Now you can serve up: Put the clementine mixture into the bottom of a wine glass, then a dollop of cream, add some syrup, drizzle with the melted chocolate, add some more meringue pieces.