Arrange oven racks toward the center of the oven, equal distance apart. Pre-heat to 300°F and line two large, rimmed baking sheets with parchment paper or Silpat™ baking sheets. Set aside.
Using a stand or hand mixer, beat the egg whites until they thicken and turn white.
While still mixing, slowly add the sugar, one or two tablespoons at a time, until each addition in thoroughly incorporated into the egg whites. Add the cream of tartar and corn starch and continue beating until the mixture is stiff and glossy.
Spoon the mixture onto the prepared baking sheets in equal-sized portions, as shown, using the back of the spoon to create an indent to place toppings after baking.
Place the baking sheets into the preheated oven for 10 minutes, then reduce heat to 225°F. Continue baking for 45 minutes, then turn off the oven. Allow pavlovas to rest in the oven for one hour without opening the door.
After one hour, remove from oven and top with whipped cream and your choice of fresh berries, mini-chocolate chips, and/or fresh herbs to garnish, if desired. Serve immediately after topping. Enjoy!