*Pavlova nest can be made in advance the night before. Store in an airtight container, or bake in the evening and leave in the oven overnight after cooling. I do not recommend trying to bake pavlova on a rainy day because it can cause your pavlova to be chewy and soft. If you must, bake it an additional 20 minutes during the last stretch of baking.
Preheat oven to 275F. Clean your mixing bowl and whisk attachment with vinegar, and line an upside-down baking sheet with parchment paper.
Place granulated sugar into a food processor and run for 60 seconds to bring it to a finer consistency.
Add egg whites, salt, and cream of tartar into your mixing bowl and begin whipping on medium low (Kitchen aid 2) for 30 seconds or until the top is foamy.
Increase the speed to medium (Kitchen Aid 4), and begin sprinkling granulated sugar in slowly over the course of a few minutes. Do not rush this step or sugar may not dissolve well. Increase speed to medium high (6 on kitchen aid) and whip for a 2-3 minutes.
Bring up the speed to high (kitchen aid 8) and whip until meringue is voluminous with stiff peaks. To test peaks, remove the whisk attachment and flip the peaks up. If they hold their shape and don’t droop over, it’s ready. You’ll also need to test that the meringue mixture is no longer grainy by rubbing a small amount between your fingers. If it’s grainy, whip for a bit longer.
Sift in the confectioners sugar and cornstarch and then whip it back to firm peaks.
Add in the cardamom and vanilla and whip for just a few seconds. If needed, use a silicone spatula to do a few folds by hand until the vanilla and cardamom are just incorporated. Do not over mix during this step or you will deflate your meringue mixture and it may become too soft.
Take a small amount of meringue and smear it under the parchment onto the four corners of the baking sheet. Press down the parchment on top to secure it.
Place meringue into a large piping bag fitted with a large round tip (like a 1A), and pipe large dollops in an organic oval shape onto the parchment paper. Use the back of a spoon to smooth out a well in the center of the oval, leaving the peaks standing on the dollops of the outer edges. (Try not to spread the well too thin, you want it to be at least 1.5" tall still)
Place in the center rack of the oven and immediately turn the temperature down to 245F. Bake for 1 hour and 20 minutes without opening the door.
Drop the temperature to 220F and bake for an additional 20 minutes.
Keeping the door closed, turn the oven off and allow the pavlova to cool for 2 hours.