Preheat oven to 290 degrees. Line 2 large baking sheets with parchment paper. Draw 3, 7-8-inch circles on the parchment paper, spacing out as much as possible ( meringue will grow slightly).
Mix the sugar and arrowroot together in a small bowl.
Mix the vanilla and vinegar together in a separate small bowl. Set aside.
In a large mixing bowl with whisk attachment, beat egg whites until stiff but not dry. Gradually add in the dry mixture, about 1 tablespoon at a time, continuing to beat well after each addition. Beat until thick and glossy. Stop mixer.
Sprinkle in wet mixture. Start mixer again and beat on medium for another 20 seconds or so just until combined and peaks remain stiff.
Prepare meringue for baking.Working from the center, spread mixture toward the outside edge, building edge slightly. This should leave a slight depression in the center which you can later fill with cream and berries!
Bake on the mid lower rack for 1 sheet, or if 2 sheets, swap trays half way through for even baking. Bake for 50-70 minutes for 1 large pavlova (or 50 to 60 minutes for mini-pavlovas). The pavlovas are done when the outsides are dry to the touch. The interior of a properly cooked pavlova should be marshmallowy, and quick tip: it's fine if cracks form in the crust.
When pavlovas have finished baking, turn off oven and open door, allowing to cool slowly over about an hour period.