Preheat oven to 150°C / 300°F (130°C fan). Set the oven shelves in the centre and lowest racks.
Draw circles on two sheets of baking/parchment paper for the Pavlova rounds.
Place egg whites in a bowl of a stand mixer and beat on Speed 8 for 1 ½ minutes until soft peaks form.
Gradually add sugar, one tablespoon at a time, while beating for 6 minutes until thick and glossy.
Add cornflour and vinegar, then beat for a further 30 seconds.
Pipe the meringue mixture into the prepared circles, creating two layers for each round.
Bake for 1 hour at 120°C/250°F, then cool in the oven for at least 3 hours.
Prepare raspberry coulis by simmering raspberries and sugar, then puree and cool.
Whip cream with vanilla and sugar until stiff just before assembling.
Layer the Pavlova rounds with cream, strawberry pillars, chopped strawberries, and raspberry coulis.
Insert a skewer for stability and repeat layering until all rounds are used.
Decorate with sprigs of rosemary, raspberries, and dust with icing sugar before serving.
