For the Pavlovas:

1. Preheat the oven to 250°F. Line a baking sheet with parchment paper; set aside.
2. In a small bowl, stir together 1 1/2 tablespoon of granulated sugar and the cornstarch; set aside.
3. In the bowl of an electric mixer fitted with the whisk attachment, beat together the egg whites and cream of tartar until soft peaks form. Beat in the vanilla. Add in the remaining granulated sugar and brown sugar, a tablespoon at a time, and beat until stiff peaks form.
4. Sift the sugar-cornstarch mixture over top and fold in with a silicone spatula.
5. Spoon the meringue onto the prepared baking sheet in 6 even mounds, about 3 inches in diameter. Make a little indented well in the center of each meringue (this is where your dulce de leche will go).
6. Bake for 45 minutes until barely golden. Turn off the oven, but the leave the meringues inside. Crack the oven door and allow them to sit in the oven for 10 minutes before removing and transferring to a wire rack to cool completely.

For the Dulce de Leche:

1. Preheat oven to 425°F.
2. Pour the sweetened condensed milk into a pie dish. Sprinkle with a pinch of salt, then cover with tin foil.
3. Place the pie dish in a large roasting pan. Fill the roasting pan with enough water to cover about half to three-quarters of the pie dish.
4. Bake for 90-120 minutes (adding more water to the roasting pan as needed), until it appears caramel brown and thick. Whisk the dulce de leche to get a smoother texture. Allow to cool before storing in the fridge.

To Assemble:

1. Fill each pavlova with 1 1/2 tablespoons of the dulce de leche. Arrange a few banana slices on top.
2. In a bowl, whip the heavy cream to soft peaks. Add in the confectioner’s sugar and whip to stiff peaks. Divide the whipped cream among the pavlovas.
3. Using a microplane, grate the chocolate over the tops of the pavlovas.