Here's a big hint: buy real parchment paper! I normally use wax paper, as it's cheaper, but no joke, the sugar just caramelized and stuck the paper to the meringue to the baking sheet. It was not pretty.
4 extra large egg whites, at room temperature
1/4 teaspoon cream of tartar
Pinch kosher salt
1 cup granulated sugar, divided
1/2 teaspoon pure vanilla extract
A melange of fresh berries to serve
Optional: greek yogurt