Chocolate Pavlova with Raspberries & Whipped Cream, ala Nigella

Ingredients for the chocolate meringue base:
6 egg whites
1 + 1/3 cups superfine sugar
3 T sifted cocoa powder
1 teaspoon balsamic or red wine vinegar
3 1/2 T dark chocolate -- finely chopped

Ingredients for the topping:
2 cups heavy cream
1 lb. raspberries
2 T coarsely grated dark chocolate

Preparing the pavlova:
Preheat oven to 350 degrees. Line a cookie sheet with parchment.

Beat the egg whites then slowly add sugar until satiny and shiny.

Sprinkle over the cocoa and vinegar, and the chopped chocolate. Gently fold everything until the cocoa is thoroughly mixed in. Mound onto a baking sheet in a fat circle approximately 9 inches in diameter, smoothing the sides and top.

Place in the oven, then immediately turn the temperature down to 300 degrees and cook for about 60 to 75 minutes. When it's ready, it should look crisp around the edges and on the sides, and be dry on top, but "when you prod the center you should feel the promise of squidginess beneath your fingers".

Turn off the oven and open the door slightly, and let the chocolate meringue cool completely.

When you're ready to serve, invert onto a big, flat-bottomed plate. whisk the cream until thick but still soft and pile it on top of the meringue, then scatter over the raspberries. Coarsely grate the chocolate into curls over the top.