Instructions

for the meringues

Adjust oven racks to upper-middle and lower-middle positions and heat oven to 250 degrees. Using pencil, draw two 8 by 4-inch rectangles on each of two 18 by 13-inch pieces of parchment paper (you will have 4 rectangles). Grease 2 rimless baking sheets and place 1 parchment on each, marked side down.
Process ¾ cup toasted blanched sliced almonds, ½ cup toasted macadamia nuts, 1 tablespoon cornstarch, and ⅛ teaspoon table salt in food processor until nuts are finely ground, 15 to 20 seconds. Add ¼ cup sugar and pulse to combine, 1 to 2 pulses; set aside.
Using stand mixer fitted with whisk attachment, whip 4 large egg whites and ¼ teaspoon cream of tartar on medium-low speed until foamy, about 1 minute. Increase speed to medium-high and whip whites to soft, billowy mounds, about 1 minute. With mixer running at medium-high speed, slowly add remaining ½ cup sugar and continue to whip until glossy, stiff peaks form, 2 to 3 minutes. Fold nut mixture into egg whites in 2 batches. Transfer meringue to pastry bag fitted with ½-inch round tip.
Follow traced guidelines to pipe meringue rectangles, then fill in rectangles with remaining meringue. Gently smooth surface of rectangles with small offset spatula. Bake for 1¼ hours. Turn off oven and allow meringue to cool in oven for 1½ hours. (Do not open oven during baking and cooling.) Remove from oven and let cool to room temperature, about 10 minutes. (Cooled meringues can be kept at room temperature, stored in airtight container, for up to 2 days.)

for the passion fruit-mango curd

While the meringue bakes, whisk 6 large egg yolks, ¾ cup passion fruit puree, ½ cup mango puree, ⅓ cup sugar, 3 tablespoons lime juice, 2 tablespoons cornstarch, and ¼ teaspoon table salt together in medium saucepan. Cook over medium heat, stirring constantly with silicone spatula and being sure to scrape into corners of saucepan, until mixture is thickened and registers 175 degrees, about 6 minutes. Off heat, whisk in 6 tablespoons unsalted cold butter, cut into pieces, until incorporated. Pass curd through fine-mesh strainer into bowl, lay parchment directly on surface of curd, and refrigerate until set, about 4 hours. (Curd can be refrigerated for up to 3 days.)

for the ganache

Meanwhile, microwave 6 ounces bittersweet chocolate, chopped fine; ¾ cup heavy cream; and ¼ teaspoon salt in bowl at 50 percent power, stirring frequently, until chocolate is melted, 1 to 3 minutes. Set aside until cooled and thickened, about 1 hour.

for the whipped cream

Using stand mixer fitted with whisk attachment, whip 1 cup cream, 2 tablespoons sugar, and ½ teaspoon vanilla on medium-low speed until foamy, about 1 minute. Increase speed to medium-high and whip until stiff peaks form, about 2 minutes. Transfer to piping bag fitted with ½-inch round tip.
Carefully peel parchment off of meringues. Dollop 1 tablespoon ganache in center of each of 3 meringues, then, working with 1 meringue at a time, use offset spatula to gently spread ganache into thin layer, leaving 1-inch border around edge. Transfer remaining ganache to second piping bag fitted with ½-inch round tip.
Dollop ⅓ cup curd in center of each topped meringue then spread to cover ganache layer. Alternating between ganache and whipped cream, pipe ½-inch tall mounds of each around perimeter of 3 topped meringues to enclose curd and ganache layers.
Apply small dab of ganache on serving platter, then top with one topped meringue, centering it on platter. Place remaining meringues one on top of the other, topped side up, then finish with remaining untopped meringue. Refrigerate, uncovered, for at least 3 hours or up to 24 hours. (Refrigerate any leftover curd and whipped cream and store leftover ganache at room temperature.)
Just before serving, decorate with remaining curd, whipped cream, and ganache. To slice, dip sharp knife in very hot water and wipe dry between cuts. Serve.