• Preheat oven to 265F / 130C/ 110 fan.
• Wipe your bowl with vinegar. Place the egg whites in the bowl and whisk on medium (I used a Kitchen aid, speed 5) for about 2 minutes until the eggs are foamy.
• Gradually add the powdered erythritol, 1 tablespoon at a time, whisking for 30 seconds before adding more (kitchen aid speed 6 or 7). Once all the sweetener has been added, scrape down the sides of the bowl with a spatula and continue whisking for about 1 minute. Add the vinegar, arrowroot and optional vanilla for a further 30 seconds - 1 minute or until still and glossy. Should be about 10 - 11 minutes from start to finish.
• Spoon the meringue onto a baking tray lined with baking paper, shaping it into a rough 22cm round with a spatula. Use the spatula to make a small indent in the center, building up the sides into a nest shape, so that it can hold the whipped cream and berries once it’s baked. (For individual pavlovas, spoon 6 rounds of meringue onto a large baking tray lined with non-stick baking paper and make shallow indents in the center.)
• Place in the oven, reduce the temperature to 215F / 100C / 80 fan and bake for 1.5 hours. Turn the oven off and allow the meringue to cool, with the door closed, for at least 3 hours to overnight to crisp up.
• Once cooled, carefully lift from the greaseproof paper.

To Decorate:

• Whisk the cream with an electric whisk until soft peaks form.
• Blitz the blackberries and half of the blueberries with a stick blender (it’s a small quantity so feel free to make more and store in the fridge to make blitzing easier).
• Spoon the whipped cream into the center of the pavlova and top with raspberries, the remaining blueberries and drizzle over the blitzed berries. Serve immediately.

Storage:

• Fridge in an airtight container for 3 - 4 days