Step 1

Place a rack in middle of oven; preheat to 200°. Beat 3 large egg whites, 1 cup (200 g) sugar, 2 tsp. Diamond Crystal or 1 tsp. Morton kosher salt, and ¼ tsp. cream of tartar in the bowl of a stand mixer fitted with whisk attachment over medium-high speed until glossy and stiff peaks form, 6–8 minutes. Add 1 tsp. vanilla bean paste or vanilla extract and beat until incorporated, about 45 seconds.

Step 2

Scrape meringue onto a rimmed baking sheet lined with a silicone baking mat or parchment paper (if using parchment, adhere to baking sheet with small dots of meringue on each corner to keep it from moving) and spread into an even layer with a large offset spatula, making sure to work into corners (the meringue is sturdy so don’t be afraid of taking your time to smooth it out perfectly). Run your thumb along the inside edge of the baking sheet to remove meringue from the metal (this will make it easier to remove later).

Step 3

Finely grate zest of 1 large lime over meringue. Bake until meringue is firm and dry to the touch and a corner pulls away easily from baking mat when lifted with offset spatula or a knife, 2–3 hours. Let cool before using, about 45 minutes. (Meringue will be chewy when warm but crisp as it cools.)Do ahead: Meringue can be baked 2 days ahead. Store tightly wrapped at room temperature. If meringue softens, heat in a 175° oven until crisp, 30–60 minutes, then let cool before using.

Step 4

Just before serving, toss 4 ripe Champagne or honey mangoes, cut into ½" pieces, 1 pint fresh raspberries, 1 Tbsp. fresh lime juice, and 2 Tbsp. sugar in a large bowl. Set fruit mixture aside.

Step 5

Beat 1 cup heavy cream, 1 cup sour cream, 1 tsp. vanilla bean paste or vanilla extract, and ½ tsp. Diamond Crystal or ¼ tsp. Morton kosher salt in a stand mixer fitted with whisk attachment on medium until soft peaks form, about 5 minutes.

Step 6

To serve, divide whipped sour cream (about ½ cup per serving) and reserved fruit with any juices among bowls. Break meringue into shards and lay on top.Do ahead: Fruit can be combined 2 hours ahead; cover and chill. Whipped sour cream can be made 12 hours ahead; cover and chill. Lightly whisk before serving.