Preheat oven to 200°F (93°C).

Line a large rimmed baking sheet with parchment paper.

In a small bowl, whisk together sugar and cornstarch.

In a large mixing bowl, using an electric mixer on medium speed, beat egg whites, lemon juice, and salt until very frothy.

Gradually add the sugar mixture, 1 tablespoon every 30 seconds, until stiff, glossy peaks form (about 8 minutes). Scrape down the sides of the bowl halfway through.

Mound the meringue onto the prepared baking sheet.

Gently spread the meringue into a 9-inch circle with a well in the center and a 1-inch raised border around the edge.

Bake until the shell is crisp on the outside and marshmallowy on the inside, about 2 1/2 hours. Reduce oven temperature to 175°F (79°C) if it starts to brown.

Turn off the oven and let the meringue dry out in the closed oven for another 2 1/2 hours, or up to overnight.

Store in an airtight container at room temperature for up to 5 days.

Just before serving, using an electric mixer, beat heavy cream and vanilla extract in a medium bowl until soft peaks form.

Fill the meringue shell with whipped cream.

Top with sliced kiwi and fresh raspberries.

To serve, use a serrated knife to cut into wedges.