• Preheat oven to 275°F / 135℃ and place a rack in the bottom 1/3 of the oven. Trace a 6-inch / 15cm circle on a piece of parchment and set it, upside down, on a baking sheet.
• In a stand mixer fitted with the whisk attachment, combine the egg whites, salt and cream of tartar (if using) and beat on medium-high speed until medium stiff peaks form, about 3 minutes.
• Turn the mixer speed to medium-low and drizzle in the water. Slowly sprinkle in the sugar a little at a time; this may take a minute or so. Turn the speed to high and whip until very stiff, glossy peaks form, about 5 minutes.
• Using the whisk attachment or a rubber spatula, gently fold the cornstarch, vanilla, and vinegar into the egg whites.
• Mound the egg foam into the circle on the prepared parchment paper. Using a metal spatula, smooth the mound, then swipe grooves into the foam, creating curls at the top. Very gently create a crater at the top, like a volcano, where the grooves meet.
• Bake for 60 minutes or until the meringue starts to turn a very pale tan color, then reduce the heat to 250°F and continue to bake for 45 minutes. Turn off the oven (don't open the door), turn on the light in the oven (don't stress if the light doesn't work) and let the meringue sit in the cooling oven for at least an hour, but it can be stored like this overnight or even up to 24 hours.
• The center of the pavlova will collapse, that's just the nature of the beast and where you will put your filling. If it does't fall into the cavity completely, use a paring knife to carefully open up a hole in the top. The outer edge may crack a touch too, but I've made this shape several times and it generally only cracks a little if you do not open the oven door. The inside should be soft, but not at all wet.
• Run a metal spatula under the pavlova to release it from the paper and carefully transfer to a serving plate.
• Fold half of the whipped cream into 1/2 cup / 130g of the lemon curd. Fit a pastry bag with a large round tip and fill with the cream-curd mixture. Alternatively, carefully spoon in the mixture. Spoon 1/4 cup / 65g of the remaining lemon curd over it, then sprinkle with some of the berries. Repeat with the remaining cream-curd mixture and then the remaining lemon curd. Finish with the remaining berries and whipped cream and then dust with confectioners' sugar.
• Refrigerate the pavlova for about 1 hour before serving to make it easier to cut.

How to Make Mini Pavlovas

• Preheat oven to 275°F. Trace eight 3-inch circles on a piece of parchment and set it in a baking sheet.
• Follow the recipe above to make the meringue.
• Mound the meringue evenly into the circles on the parchment.
• Bake at 275°F for 15 minutes or until the meringue starts to turn a very pale tan color, then reduce the heat to 225°F and continue to bake for 30 minutes. Turn off the oven (don't open the door), turn on the light in the oven (don't stress if the light doesn't work) and let the meringue sit in the cooling oven for a couple hours, or even overnight.
• Fill and decorate as noted above. You can assemble these a few hours before serving. They actually benefit from some time in the refrigerator.