Preheat your oven to 225°F (110°C) and prepare a large baking tray with parchment paper.
In a large bowl, beat the egg whites with a mixer on medium speed for about 5 minutes until soft peaks appear.
Gradually mix in the powdered sweetener, one spoonful at a time, until stiff, glossy peaks form.
Carefully fold in the cornstarch, vinegar, and vanilla extract with a rubber spatula until well combined.
Spoon the meringue onto the tray, shaping it into an 8-inch circle with higher edges.
Bake for 90 minutes until firm and slightly golden, then turn off the oven and let it cool inside for 1 hour.
Once cooled, transfer the pavlova to a wire rack to cool completely.
Before serving, top with keto whipped cream, cream cheese frosting, and fresh berries.
Slice and enjoy this delightful low-carb dessert!