Preheat oven to 350°; once preheated, reduce to 200°. Using a mixer, beat egg whites with cream of tartar on medium-high until frothy. While the mixer is on, slowly add in the granulated sugar and mix until medium peaks form. With the mixer on medium, slowly add in confectioners’ sugar, 1 tablespoon at a time, until your meringue is at stiff peaks. Spread meringue in an 8-inch circle on a parchment-lined baking sheet, making a well in the middle. The sides should be about 2 inches high and the middle about 1 inch. Bake in a 200° oven for 3 hours. Once baked, turn oven off and let pavlova cool in the oven for 2–3 hours.
Note: Pavlova can be made a day ahead and stored in an airtight container.
Citrus and Berry Topping:
Thirty minutes before you are ready to eat your pavlova, toss berries, mint, zest and sugar together. Toss in tangerines and kumquats right before topping. With a slotted spoon top pavlova with berry and citrus mixture and drizzle with the reserved fruit juices.