Position oven rack in bottom third of oven. Preheat oven to 300°F (150°C). Draw a 9-inch circle on a piece of parchment paper, and place upside down on a baking sheet.

In the bowl of a stand mixer fitted with the whisk attachment, beat egg whites, salt, and cream of tartar at medium speed until foamy. With mixer on high speed, slowly and gradually add sugar, beating until combined. Beat in cornstarch and vanilla. Increase mixer speed to high, and beat until stiff peaks form, about 4 minutes. Spoon meringue into center of drawn circle on prepared pan. Using an offset spatula or a spoon, spread meringue to edges as desired, making a shallow indentation in center to create a bowl shape. Place in oven.

Immediately reduce oven temperature to 250°F (130°C). Bake until exterior is completely set and does not feel sticky, about 1 hour and 50 minutes. (Be careful to open the oven as little as possible when checking.) Turn oven off, and leave Pavlova in oven with door closed until completely cool, at least 5 hours, preferably overnight.

Carefully peel parchment paper off Pavlova; place on a serving plate. Top with Coconut Rum Whipped Cream and Pineapple Curd. Garnish with cherries, if desired. Serve immediately.

In the bowl of a stand mixer fitted with the whisk attachment, beat cold cream and confectioners’ sugar at medium-high speed until stiff peaks form, 3 to 4 minutes. Beat in rum and extracts until combined. Use immediately.

In a small saucepan, bring pineapple juice to a boil over medium-high heat. Cook, stirring occasionally, until reduced by half, about 10 minutes. Let cool completely.

Whisk sugar, egg, egg yolks, lemon juice, and cornstarch into pineapple juice. Bring to a boil over medium-high heat; cook, stirring constantly, until thickened, 2 to 3 minutes. Strain curd through a fine-mesh sieve into a heatproof bowl, discarding any solids. Add butter, and whisk until smooth and combined. Cover with plastic wrap, pressing wrap directly onto surface of curd to prevent a skin from forming. Refrigerate until cool and ready to use, at least 2 hours or up to 3 days.