Preheat the oven to 300 degrees F. Line a baking sheet with parchment paper.
Place the egg whites in the bowl of an electric mixer fitted with a whisk attachment. Whip on medium-high speed until stiff, about 3 minutes. Add the granulated sugar 1 tablespoon at a time, mixing well after each addition. The egg whites should look very thick and hold a soft peak. Turn the mixer off and add the buttermilk, cornstarch, 1 tablespoon of the honey and 1 teaspoon of the vanilla. Mix on low just to combine.
Dollop the egg white mixture onto the center of the prepared baking sheet. Pushing outwards with a small offset spatula, spread the mixture into a circle about 9 inches in diameter. Bake until set and slightly golden, about 1 hour. Cracking on the outside of the pavlova is normal. Allow to cool completely on the baking sheet before removing, about 2 hours
Meanwhile, pour the heavy cream into the bowl of an electric mixer fitted with a whisk attachment. Add the confectioners' sugar and remaining 1 teaspoon vanilla extract. Whip on high until soft peaks form, 2 to 3 minutes. Chill until ready to serve.
Add the mango, pineapple, blueberries and kiwis to a mixing bowl and toss gently to combine.
Carefully lift the pavlova from the parchment and place on a serving platter. Dollop the whipped cream onto the center. Use a small offset spatula to spread the cream outwards, leaving a slight rim of exposed pavlova on all sides. Top the cream with a mound of fresh fruit. Drizzle the pavlova with the remaining 1 tablespoon honey and serve immediately.
Use a pen to trace around the rim of a 9-inch cake pan on the parchment paper. Flip the paper over and use the circle as a guide when spreading the egg white mixture.