How to Make It
Preheat the oven to 180°F.
Place the egg whites in the bowl of a stand mixer with a whisk attachment. Mix over high speed for 2 minutes, or until egg whites are foamy and beginning to stiffen.
Slowly incorporate 2 cups sugar while still mixing on high speed. Mix for 3 to 4 minutes more, or until stiff peaks form. Fold in cornstarch and vanilla until just combined.
Spoon mixture onto a baking sheet lined with parchment paper and form into a 9- to 10-inch circle. Bake for 1 hour and 30 minutes, and then turn off the oven. Whatever you do, DO NOT OPEN THE OVEN DOOR. Let the pavlova sit in the oven for 1 hour before removing.
Meanwhile, segment the oranges over a bowl to catch any juice that falls. Reserve the segments and squeeze the remaining juice out of the oranges before discarding.
Combine the orange juice, pomegranate juice, and ¼ cup plus 2 tablespoons sugar in a small saucepan. Cook over medium heat until the sugar is dissolved and mixture begins to thicken. Turn off the heat and stir in 1 to 2 tablespoons of heavy cream. Reserve sauce.
Place remaining heavy cream and remaining 2 tablespoons in the bowl of a stand mixer. Using the whisk attachment, mix over high speed for 8 to 10 minutes or until stiff peaks.
Remove the pavlova from the oven and spread whipped cream over top. Top with syrup, reserved orange segments and pomegranate seeds.