Whisk the egg white until soft peaks form, then gradually add the caster sugar one spoonful at a time while whisking.
On a baking tray lined with greaseproof paper, place half the meringue mixture and shape it into a circle about 20cm in diameter. Using a spoon, place dollops of the remaining meringue around the edge of the circle and use a skewer to create peaks on them.
Bake at 140°C (Gas Mark 1) for one hour, then turn off the oven and leave the pavlova inside to cool; this creates a crisp shell and a soft centre.
When ready to serve, whisk all the filling ingredients together in a bowl.
Place about a third of the strawberries in a food processor with the sugar and blend into a sauce, then strain through a sieve.
Place the pavlova on a plate and fill with the vanilla cream; chop the remaining strawberries to decorate the pavlova, then dust with icing sugar and drizzle a little of the purée over the strawberries.