Line 2 baking sheets with parchment paper and preheat the oven to 350°F.
In a squeaky clean bowl with a hand mixer or in a stand mixer with a paddle attachment, beat eggs whites on medium speed until the whites form soft peaks.
In 1 tablespoon amounts, slowly add the sugar in a little at a time while beating until stiff glossy peaks form. Turn off mixer and gently fold in cornstarch and cream of tartar with a spatula, then add vanilla and fold.
Transfer mixture into a piping bag fitted with a large tip (I used Ateco 867 tip) and pipe 10 mounds leaving a whole in the middle of each one, so whipped cream can be placed there later. (5 on one baking sheet and 5 on the other) Or you can spoon 10 large dollops, again leaving a whole in the middle.
Bake for 5 minutes at 350°F then switch the oven temperature to 200°F and bake for 35-40 minutes.
Banana Whipped Cream
Beat heavy cream in a large bowl on high speed until light peaks form. Then, slowly add in sugar and mix until stiff peaks form, add in vanilla and mix. Fold in well mashed banana in the whipped cream (make sure the banana is mashed to a liquid consistency before folding.)
Spoon the banana whipped cream into the center of the pavlovas. Melt peanut butter for 30 seconds in the microwave and drizzle on top. Add thin slices of the remaining banana on top. Feel free to add chocolate shavings or chocolate chips. Enjoy!