Separate egg whites from 4 eggs into a bowl. Let the whites sit out until they are room temperature.

Preheat oven to 275 degrees.

Line a cookie sheet with wax paper. Use a glass to trace 6 three inch circles onto the parchment paper. Flip the paper over so the side you drew on is facing the cookie sheet. (So you don't get marker/pen on your pavlova.)

In a small bowl, whisk together the sugar and cornstarch. In another small bowl, combine the vanilla and vinegar.

In a clean mixing bowl, whip egg whites until they reach soft peak stage. Begin adding the sugar/cornstarch mixture a couple tablespoons at a time. Keep whipping until you have added all of the sugar. (The peaks should begin to stiffen.)

Sprinkle the vinegar/vanilla mixture over the eggs. Whip until combined and eggs look shiny with stiff peaks.

Use a spatula or large spoon to scoop the meringue into the circles made on the cookie sheet. Spread meringue up the edges of the circles, smoothing out any small peaks. Make a slight depression in the meringue in the center of each circle (for filling later).

Place meringues in the oven and immediately turn the heat down to 250 degrees Fahrenheit. Bake for 45-55 minutes or until meringues sound hollow when tapped.

Leave the meringues in the oven but turn off the heat and leave the oven door ajar. Let meringues cool completely in the oven.

To make the sauce, heat the blueberries, lemon juice, and sugar in a medium saucepan over medium-high heat. Stir occasionally. After about 5 minutes, the berries should begin to break down and form a sauce. Use a potato masher to break apart the berries even more. Once a thick sauce is formed turn off heat and stir in the brandy. Set aside to cool.

To assemble the pavlova, top each meringue with a 1/4 cup of fresh blueberries and pour cooled sauce over top.