Preheat the oven to 250°F (120°C) and line a baking sheet with parchment paper.

In a large bowl, beat the egg whites with an electric mixer until stiff peaks form.

Gradually add the caster sugar, cornstarch, vinegar, and vanilla extract while continuing to beat until the mixture is thick and glossy.

Spoon the mixture onto the prepared baking sheet, shaping it into a Christmas tree shape.

Bake for 1 hour 30 minutes or until the pavlova is crisp on the outside and soft on the inside. Turn off the oven and leave the pavlova inside to cool completely.

In a separate bowl, whip the heavy cream, powdered sugar, and vanilla extract until soft peaks form.

Transfer the pavlova to a serving platter and top with the whipped cream.

Decorate with assorted fresh berries to resemble ornaments on a Christmas tree.

Serve and enjoy!