Preheat the oven to 300°F (150°C). Line a baking sheet with parchment paper. Trace a 7-inch (18 cm) circle onto the parchment, then flip it so the pencil marks are underneath. This gives you a guide without the graphite touching your meringue.Tip: I usually grab a dinner plate to trace around it’s the perfect size. In a large, clean bowl (no grease, not even a smudge!), beat the egg whites on medium speed until soft peaks form.
Gradually add the sugar, one tablespoon at a time, while beating on high speed. This step takes about 8–10 minutes, and it’s worth being patient. You want glossy, stiff peaks that feel smooth when you rub a little between your fingers no graininess.
Sprinkle in the cornstarch, add the vinegar and vanilla, and fold gently until everything is combined.Mom tip: don’t rush the sugar addition. Adding it slowly gives you that perfect pavlova texture crisp outside, soft inside. Spoon the meringue into the center of your traced circle. Use the back of the spoon to shape it into a nest with slightly higher edges (this helps hold all that luscious cream later).
Pop it into the oven, then immediately reduce the temperature to 225°F (110°C). Bake for 60 minutes.
Once the timer’s up, turn off the oven but don’t open the door. Let the pavlova cool inside for 1 hour. This gentle cooling prevents cracks.
In a chilled bowl, beat together the heavy cream, mascarpone, powdered sugar, and vanilla until soft peaks form. Keep it in the fridge until you’re ready to assemble.The mascarpone makes this cream extra rich and stable it holds up beautifully on top of the pavlova. Carefully transfer the cooled pavlova to a serving platter. (I slide a wide spatula underneath and gently shimmy it onto the plate.)
Spread the whipped cream mixture generously over the top, then scatter your fresh berries.
Serve immediately or pop it in the fridge for up to 2 hours, uncovered, so the meringue stays crisp.
