Grapefruit Meringue Stacks

1. Make the Meringues: Preheat the oven to 325°F. Line two baking sheets with parchment paper. Place the egg whites and cream of tartar in a large bowl, and using a hand mixer, whip on medium speed until foamy, about 3 minutes. While whipping, gradually add the sugar in a slow, steady stream, then increase the speed to high and whip until the meringue holds medium peaks, 5 to 7 minutes. Add the vanilla and salt, and mix to combine. Transfer to a piping bag fitted with a large star tip.

2. Pipe the meringue into 12 rosettes on the prepared baking sheets (no need to be exact, but aim for about 3½ inches wide). Transfer to the oven, and immediately lower the temperature to 250°F. Bake until the meringues are dry to the touch, 45 to 90 minutes. Cool completely on the baking sheets.

3. Make the Curd: While the meringues are baking, in a medium saucepan, melt 4 tablespoons (56g) of the butter over medium heat. Add the grapefruit juice, yolks, sugar and salt, and whisk to combine.

4. Reduce the heat to medium-low, and continue to cook, stirring constantly with a silicone spatula, until the mixture is thick enough to coat the spatula, 4 to 6 minutes (it should hold a clean line when you draw your finger through it). Stir in the remaining 1 tablespoon (14g) butter, then strain the curd into a heat-safe container. Cover with plastic wrap directly on the surface, and refrigerate until fully chilled, at least 1 hour.

5. Make the Whipped Cream: In a medium bowl, whip the heavy cream and confectioners’ sugar to medium peaks. Add the vanilla and mix to combine.

6. Place one meringue on a plate, top with about 1 tablespoon grapefruit curd and spread it into an even layer. Top with another meringue, then more curd. Repeat once more, making three layers per stack (and four stacks total). Top each with a dollop of whipped cream, garnish with a slice of grapefruit, if desired, and serve immediately.