Preheat oven to 150 degrees C. Line an oven tray with baking paper.
Beat egg whites with an electric stand mixer or hand mixer until soft peaks form.
Add sugar, one tablespoon at a time. Beat until it dissolves and foam is stiff, thick and glossy. Beat in lemon juice or vinegar and vanilla.
Spread onto tray to form a 23cm mounded circle. Bake for 30 minutes. Reduce oven to 120 degrees C, then bake for further 45 minutes. Allow to cool in a turned-off oven, with door open, to dry completely.
Top with cream and berries. Drizzle with passionfruit just before serving.