Position a rack in the bottom third of the oven; preheat to 250°F.

Line a baking sheet with parchment paper.

In a small bowl, mix superfine sugar, cornstarch, and ground cardamom.

Scrape the seeds from the vanilla bean into the bowl and mix well.

In a large bowl, using an electric mixer on medium speed, beat the egg whites until foamy.

Gradually add the sugar mixture, 1 tbsp.

at a time, beating until the meringue is glossy (about 5 minutes).

Add the chopped pistachios and vinegar; fold until blended.

Spoon the meringue onto the prepared baking sheet, spreading it into an 8-inch round and creating swirls as you spread.

Form a shallow well in the center.

Bake until crisp on the outside but tender on the inside, about 2 hours.

Let the meringue cool on the baking sheet on a wire rack.

For the topping, in a medium bowl, toss the fruit with sugar.

Let it stand until the fruit releases juices, about 20 minutes.

In a large bowl, using an electric mixer, beat the cream until firm peaks form.

Fold in the crème fraîche and lemon zest and juice.

Transfer the cooled meringue to a platter.

Fill the center with the whipped cream.

Top with the fruit.