Martha and Michel Roux prepare a classic meringue with Italian plum dessert.
Using a small knife, remove the pits from plums without cutting plums entirely in half. Place plums in a medium heatproof bowl. Bring stock syrup and bay leaves to a boil in a small saucepan over medium heat. Immediately pour syrup over plums and let cool completely.
Preheat oven to 250 degrees. Line a baking sheet with a nonstick baking mat or parchment paper; set aside.
In the bowl of an electric mixer fitted with the whisk attachment, beat egg whites until soft peaks form. With the mixer on low, slowly add superfine sugar; increase speed and continue whisking until firm peaks form. Add confectioners' sugar and beat until meringue is smooth and shiny and stiff peaks form, 6 to 8 minutes.
Drain plums and pat dry with paper towels, removing as much syrup as possible. Gently fold plums into meringue mixture.
Using two large spoons, scoop one-quarter of the meringue mixture and pass it between both spoons to form a rounded oval shape; transfer to prepared baking sheet. Repeat process with remaining meringue. Transfer to oven and bake for 2 hours.
Cool meringues slightly on baking sheet; carefully transfer to a wire rack and let cool completely in a dry place before serving.