• Preheat oven to 230°F (110°C), conventional, no fan. Place the rack in the middle of the oven.
• Line a baking tray with parchment paper. Draw a 7-inch (18cm) circle on the parchment, then flip it over.
• Place egg whites and salt in a clean, grease-free bowl.
  
• Whip on medium speed until soft peaks form.
  
• Increase speed to medium-high and add sugar 1 tablespoon at a time, beating well between additions.
  
• Continue beating for 5–7 minutes, until the meringue is very stiff and glossy and is holding sharp peaks.
  
• It must be completely smooth, no sugar grains when rubbed between fingers.
  
• Sprinkle the cornstarch over the meringue, add vinegar and vanilla.
  
• Mix for 1 more minute just until incorporated.
  

Shape a Tall Pavlova

• Fix the parchment paper with a bit of meringue.
  
• Spoon the meringue onto the prepared circle.
  
• Using a spatula, push the meringue upward, building height in the center.
  
• Create decorative vertical ridges by holding a spatula or the back of a spoon vertically against the sides and gently pulling upward.
  
• Create a shallow indentation on top for the cream, keeping the edges thicker.
  

Bake and cool

• Place pavlova in the oven. Bake for 1 hour 30 minutes. Do not open the oven during baking.
• Turn the oven off, crack the door slightly, and leave the pavlova inside to cool at least 2 hours or overnight. The pavlova should be pale, dry to the touch, and crisp on the outside.
  

Prepare the Mascarpone cream

• In a bowl, add mascarpone with powdered sugar and vanilla.
  
• Mix just until smooth.
  
• Add the cream and whip on medium speed until stiff peaks form.
  
• Stop immediately once the cream holds its shape and looks silky.
  

Assemble the pavlova

• Spoon mascarpone cream generously over the pavlova.
  
• Top with fruit and festive garnishes. Dust with powdered sugar.
  
• Assemble up to 2 hours before serving.