4 egg whites, room temperature
¼ c. granulated sugar
¾ c. packed light-brown sugar
1 tsp. distilled white vinegar
Pinch of kosher salt
1 tsp. pure vanilla extract
Preheat oven to 300° F. Line a baking sheet with parchment paper. Use a cake pan as a guide to trace an 8” circle on it. Turn marked side down.
Place egg whites, brown sugar, and salt in the bowl of a mixer fitted with the whisk attachment. Beat on low speed until well combined and no lumps of sugar remain. Increase speed to medium; beat until soft peaks form, about 9 minutes. With mixer running, gradually add granulated sugar. Continue beating until peaks are stiff and glossy, about 2 minutes more. Beat in vinegar and vanilla.
Secure marked parchment paper to baking sheet with a bit of meringue under each corner. Spread remaining meringue onto marked 8” circle; form peaks around edge and a well in center. Bake until meringue is crisp around edges and just set in center, about 1 hour and 15 minutes. Turn off oven and let cool inside 2 hours. Transfer sheet to a wire rack; let stand until meringue is cool enough to handle. Carefully peel meringue off parchment paper and cool completely on rack.
1 c. granulated sugar
1 tsp. pure vanilla paste or extract
¼ c. fresh lemon juice
3 peaches (1 pound), halved
Meanwhile, prepare an ice-water bath. In a saucepan, combine granulated sugar, lemon juice, vanilla, and 2¼ cups water. Bring to a simmer over medium-high heat and cook, stirring, until sugar has dissolved. Remove peach pits and add (cut-sides up), covering with a parchment round to keep them submerged. Reduce heat to low and simmer until peaches are tender when pierced with the tip of a knife, 8 to 10 minutes.
Transfer peaches to a plate with a slotted spoon. When cool enough to handle, peel, and discard skins. Bring poaching liquid to a boil; cook until thickened and reduced by half (you should have 1 cup), about 10 minutes. Transfer to a medium bowl and chill in ice bath until cold.
1 c. heavy cream
1 Tbsp. granulated sugar
In a bowl, beat heavy cream with granulated sugar on medium speed until stiff peaks form. To assemble, carefully place meringue on a serving platter. Spoon whipped cream on top, spreading to edges; then add peaches, cut- sides down. Drizzle with syrup, slice into wedges, and serve immediately.