For the Meringues

• 4 large egg whites, at room temperature
• ¼ teaspoon cream of tartar
• pinch of salt
• ⅔ cup superfine sugar
• 1 teaspoon vanilla
• ⅔ cup confectioners’ sugar, sifted

For the Eton Mess

• 1 pound fresh strawberries, sliced
• 2 cups frozen strawberries, thawed
• 1 cup confectioners’ sugar, sifted
• 2 cups heavy cream
• ½ cup sour cream
• 10 to 15 two-inch meringue cookies, homemade or store-bought

Prepare the Meringues at Least One Day Before Serving Final Dessert.

To Make the Meringues: Position a rack on the middle shelf of the oven and place a second rack on the top shelf. Preheat the oven to 250°F. Line two baking sheets with parchment paper.

In a Large Metal Bowl, beat the egg whites and cream of tartar with an electric mixer set at low speed until foamy. Add the salt, increase the mixer speed to medium-high, and continue beating until soft peaks form. Add the superfine sugar 1 tablespoon at a time, beating constantly until stiff peaks form. Beat in the vanilla.

Sift the Confectioners’ Sugar a Second Time Over the Egg Whites. Using a rubber spatula, carefully fold the sugar into the egg whites just until no streaks of confectioners’ sugar remain. Do not overmix, as this will deflate the meringue.

Using a Large Serving Spoon, scoop 8 to 10 large ¼-cup portions of the meringue onto each prepared baking sheet.

Place Both Sheets of Meringues in the Oven. Reduce the oven temperature to 200°F and bake until very crisp, about 2 hours. Baking the meringues for a long period of time at a low temperature assures that they will remain white and become very crisp. If the meringues begin to color, prop the oven door open with the handle of a wooden spoon. When the meringues are done, turn the oven off and let them cool in the oven for at least 1 and up to 6 hours.

Use Immediately, or store the cooled meringues in a tightly covered container for up to 1 week.

To Make the “Mess”: Place the fresh strawberries in a large bowl. Set aside. Process the thawed frozen strawberries in a blender or food processor until they form a thick purée. Stir ½ cup of the confectioners’ sugar into the purée. Toss the fresh strawberries with sweetened strawberry purée.

Using an Electric Mixer Set at Medium Speed, whip the cream and remaining confectioners’ sugar together in a chilled bowl until soft peaks form, about 4 to 5 minutes. Use a rubber spatula to fold in the sour cream.

Break Meringue Cookies Into Large, bite-size pieces. Fold the meringues and cream into the strawberries just until combined. Do not overmix; the finished dessert should be a billowy, pink-streaked confection, with visible chunks of ruby berries and crunchy chunks of meringue. Spoon the dessert into a large serving bowl and serve immediately.