Blackberry-Basil Pavlova with White Chocolate Ganache and Balsamic Reduction

Preheat oven to 250°F (120°C). Line a baking sheet with parchment paper and draw an 8-inch circle on the paper. Turn the parchment over so the pencil mark is facing down.

In a stand mixer fitted with the whisk attachment, beat 6 large egg whites and 1/4 teaspoon cream of tartar on medium speed until soft peaks form, about 2 minutes.

Gradually add 1 1/2 cups superfine sugar, 1 tablespoon at a time, while beating on high speed. Continue beating until the meringue is glossy and stiff peaks form, about 5-6 minutes.

Sprinkle 1 tablespoon cornstarch, 1 teaspoon white vinegar, and 1 teaspoon vanilla extract over the meringue and gently fold in with a rubber spatula.

Spoon the meringue onto the parchment paper, using the circle as a guide. Shape into a disk with a slight depression in the center.

Bake for 1 hour and 15 minutes, or until the outside is crisp and dry. Turn off the oven, crack the door open, and allow the pavlova to cool completely in the oven, about 1 hour.

While the pavlova is cooling, prepare the balsamic reduction. In a small saucepan, combine 1 cup balsamic vinegar and 2 tablespoons honey. Bring to a simmer over medium heat and cook until reduced by two-thirds and syrupy, about 15-20 minutes. Set aside to cool.

For the white chocolate ganache, place 8 ounces chopped white chocolate in a heatproof bowl. Heat 1/2 cup heavy cream in a small saucepan just until it begins to simmer. Pour over the chocolate and let stand for 1 minute, then stir until smooth. Fold in 4 ounces mascarpone cheese until well incorporated. Refrigerate for 20 minutes, stirring occasionally, until slightly thickened but still spreadable.

In a food processor, pulse 1/2 cup of the blackberries with 1/4 cup fresh basil leaves, 1 teaspoon lemon zest, and 1/4 teaspoon salt until finely chopped but not pureed.

Gently fold the blackberry-basil mixture into the remaining 2 1/2 cups whole blackberries.

To assemble, carefully transfer the cooled pavlova to a serving platter. Spread the white chocolate ganache over the depression in the pavlova.

Spoon the blackberry-basil mixture over the ganache, allowing some to cascade down the sides.

Drizzle with the balsamic reduction, reserving some for serving.

Garnish with reserved 1/2 cup fresh blackberries and 8 fresh basil leaves.

Serve immediately, offering additional balsamic reduction on the side.