01 - Preheat oven to 300°F. Line a baking sheet with parchment paper and draw a 9-inch circle as a template. Flip the parchment over so the ink doesn't contact the meringue.
02 - In a clean, dry bowl, beat the egg whites on medium speed until soft peaks form. Ensure no yolk contamination occurs for proper volume development.
03 - Add the superfine sugar one tablespoon at a time while beating continuously. Continue until the meringue becomes thick, glossy, and all sugar granules have dissolved.
04 - Sprinkle the sifted cocoa powder, vinegar, and chopped dark chocolate over the meringue. Gently fold together with a rubber spatula until just combined, maintaining as much air as possible.
05 - Spoon the chocolate meringue onto the prepared parchment within the drawn circle. Form a nest shape with slightly higher edges to create a well for the toppings.
06 - Place in the oven and immediately reduce temperature to 250°F. Bake for 1 hour 15 minutes. Turn off the oven, prop the door slightly ajar, and allow the pavlova to cool completely inside to prevent cracking.
07 - Shortly before serving, whip the cold heavy cream with powdered sugar and vanilla extract until soft peaks form. Avoid overwhipping to maintain a light, fluffy texture.
08 - Gently spread the whipped cream over the cooled meringue base. Top with fresh raspberries and scatter chocolate shavings over the surface for an elegant finish.