Step 1: Preheat your oven to 250°F (120°C) and line a large baking sheet with parchment paper. Draw an 8-inch circle on the paper as a guide.
Step 2: In a clean glass or metal bowl, whisk the egg whites and cream of tartar on medium speed until soft peaks form.
Step 3: Increase the speed and add the caster sugar one tablespoon at a time, whisking until the mixture is thick, glossy, and the sugar has fully dissolved.
Step 4: Gently fold in the cornstarch and vanilla extract using a spatula to maintain the air in the blood orange pavlova recipe base.
Step 5: Spread the meringue onto the prepared parchment paper, using the circle as a guide. Build up the sides slightly to create a nest.
Step 6: Lower the oven temperature to 225°F (110°C) and bake for 90 minutes. Turn off the oven and let the meringue cool completely inside with the door slightly ajar.
Step 7: In a small saucepan, simmer the juice from one blood orange with 2 tbsp of sugar until reduced by half into a thick syrup. Let cool.
Step 8: Whip the heavy cream with blood orange zest until stiff peaks form. Spread over the cooled meringue.
Step 9: Top with blood orange segments and drizzle with the prepared syrup right before serving.