Line a flat baking tray with paper. Preheat oven to 150°C.
Ensure TM bowl and butterfly are immaculately clean and dry before beginning.
Place egg whites and cream of tartar into TM bowl and whip 5 min/37°C/Butterfly/ speed 3.5.
Whip 6 min/37°C/Butterfly/speed 3 while adding the sugar 1 tbsp at a time through hole in lid. Occasionally stop and scrape down sides of bowl with a flat silicone spatula (not the TM spatula).
Add cornflour, vinegar and vanilla and whip 1 min/37°C/Butterfly/speed 3.
Spread the mixture in a circle on the prepared tray mounding it up as high as possible. It will flatten as it bakes. Dust with enough of the cocoa powder to make an impact. Reserve the rest for the cream.
Bake pavlova for 50 minutes. Turn oven off and leave in oven for up to 3 hours or completely cold. Remove from oven and try not to move it until you are ready to assemble and serve.
To serve, whip cream with remaining cocoa powder to soft peaks, remove from TM bowl, leaving a little in the bowl, and then add chocolate and vanilla to bowl. Melt 4 min/50°C/speed 1.
Return cream to the bowl and incorporate 4 sec/speed 4.
Fill the hollow, top with heaps of fruit and if you have some ganache laying around...drizzle on!