Step 1

To prepare lemon curd: Whisk whole egg, 2 egg whites, granulated sugar, lemon zest and lemon juice in a medium nonreactive saucepan (see Tips). Add butter and cook over low heat, whisking constantly, until the mixture is thick enough that drawing your finger across a coated spoon leaves a mark, 5 to 12 minutes. Do not let the sauce come to a simmer. Pour the hot curd through a fine-meshed sieve into a small bowl, pressing on the solids. Let cool slightly and refrigerate until chilled, about 4 hours.

Step 2

To prepare meringue: Preheat oven to 250 degrees F. Line a large baking sheet with parchment paper. Draw a 9-inch circle with a pencil in the center of the paper to use as a guide for your pavlova, then turn the paper over so it's pencil-side down.

Step 3

Beat 4 egg whites, cream of tartar and salt in a large bowl with an electric mixer on medium speed until soft peaks form. Increase the mixer speed to high and gradually beat in superfine sugar. Continue beating until stiff and glossy. (See Tips.)

Step 4

Use the back of a spoon or a rubber spatula to spread the meringue into a 9-inch circle (using the guide) on the parchment. Smooth and level the center and make the edges slightly higher so there is a shallow depression in the middle. (It does not have to be completely smooth.) Bake the meringue for 1 hour.

Step 5

Reduce the oven temperature to 200 degrees and continue baking for 1 hour more. The meringue should feel firm when gently touched.

Step 6

Turn off the oven, leave the door ajar and let the meringue sit in the oven until cool, about 1 hour. (As it cools, the exterior will crack in spots.)

Step 7

To prepare topping: Just before serving, whip cream in a small bowl with an electric mixer until starting to thicken. Add confectioners' sugar and continue whipping until soft peaks form.

Step 8

To assemble pavlova: Use a large spatula or chef's knife to carefully separate the meringue from the parchment and slide it onto a large flat serving platter. Fill the center depression with the lemon curd and pile the whipped cream in the center of the curd. Cut into wedges with a sharp knife. Serve immediately.