Begin by preheating your oven to 250°F. Place the oven rack in the center position. Line a baking sheet with parchment paper and trace a 9-inch circle onto it using a dark marker and a 9-inch round object like a cake pan or plate. Flip the parchment over so the ink side is facing down to prevent it from coming in contact with the meringue.

In the clean, dry bowl of a stand mixer, beat the egg whites on medium speed until they become frothy, approximately 1 minute. Add the salt and cream of tartar, and continue whisking until soft peaks begin to form, roughly 2 minutes. Slowly incorporate the sugar, adding 1 tablespoon at a time. This process should take about a minute to ensure proper incorporation. Increase the mixer speed to medium-high and continue whipping until the meringue turns glossy and forms stiff peaks, around 5 to 7 minutes. You’ll know it’s ready when the peaks hold their shape without drooping as you lift the beater. Blend in the vanilla extract and cornstarch, mixing for another 30 seconds.

To secure the parchment, dab small portions of meringue under its corners to “glue” it to the baking sheet. Spoon the meringue into the center of the traced circle and use a spatula to shape it, slightly indenting the middle to hold the whipped topping later. Keep the edges rustic and don’t worry about achieving a flawless surface a little texture adds charm.

Bake the meringue for 85 to 90 minutes, or until it’s crisp on the outside and fully dry. Some minor cracks may form, which is perfectly fine. Turn off the oven, leaving the meringue inside to cool gradually with the oven door propped open for at least 1 hour. This slow cooling method helps minimize shrinkage and preserves the meringue’s structure.

Clean the mixing bowl thoroughly before moving on. Add the mascarpone, heavy cream, granulated sugar, vanilla extract, and lemon zest to the bowl. Begin mixing on low speed to combine the ingredients without splattering. Once combined, increase the speed to medium-high and beat until the mixture reaches soft, billowy peaks about 1 to 2 minutes. Be vigilant not to overwhip, as the cream could become grainy or too stiff. The texture should remain smooth and silky.

Carefully detach the meringue from the parchment paper and transfer it to a serving platter. If the meringue sticks, simply trim the parchment to fit neatly beneath and serve it as-is.

Generously mound the mascarpone whipped cream into the center of the meringue, spreading it gently toward the edges while leaving a 1-inch border. It’s okay if the meringue cracks slightly during assembly the cream and berries will disguise any imperfections.

Top the pavlova with your choice of fresh mixed berries or macerated fruit, allowing some to cascade naturally over the edges. If desired, finish with a few mint leaves for a touch of color and freshness.