01 - Preheat oven to 300°F. Line a baking sheet with parchment paper and draw a 9-inch circle as a guide.
02 - In a clean, dry bowl, beat egg whites with an electric mixer on medium speed until soft peaks form.
03 - Gradually add sugar, one tablespoon at a time, beating until stiff, glossy peaks form and the sugar is completely dissolved.
04 - Gently fold in the sifted cocoa powder, vinegar, and finely chopped dark chocolate with a spatula.
05 - Spoon the meringue onto the prepared circle on the baking sheet, smoothing the sides and creating a slight well in the center.
06 - Bake for 1 hour 15 minutes. Turn off the oven, leave the door slightly ajar, and allow the meringue to cool completely inside the oven.
07 - To prepare the topping, whisk the heavy cream with powdered sugar and vanilla extract until soft peaks form.
08 - Carefully transfer the cooled meringue to a serving platter. Top generously with the whipped cream, then scatter fresh raspberries over the cream. Finish with dark chocolate shavings or grated chocolate.
09 - Serve immediately to enjoy the crisp texture of the meringue.