Preheat the oven to 150°C (130°C for fan oven). Whisk the egg whites until they start to go frothy white. As soft peaks start to form add one tablespoon of sugar at a time until it is all incorporated. The mixture will go stiff and glossy. Add the vanilla extra and continue whisking until the sugar is completely dissolved and the mixture holds stiff peaks. You will know the sugar is dissolved when you rub a little bit of the mixture between your fingers and it does not feel gritty.
Pipe the mixture onto a baking tray lined with grease proof parchment and bake for about an hour or until golden. Instead of piping the mixture you can also just spoon it onto the parchment in blobs.