Preheat the oven to 110°C and line two large baking trays with baking parchment.
In a clean, dry bowl, whisk together 2 tbsp meringue powder and 120 ml warm water on low speed for about 30 seconds until foamy.
With the mixer on medium–high speed, add the caster sugar one tablespoon at a time, allowing each addition to dissolve before adding the next.
Add the vanilla extract and a pinch of salt, then increase to high speed and beat for 5–7 minutes until stiff, glossy peaks form.
Spoon or pipe the meringue onto the prepared trays, leaving space between each one.
Bake for 1 hour without opening the oven door. Once baked, switch off the oven, prop the door ajar and leave the meringues to cool inside for at least 1 hour (or preferably overnight) until crisp.
Once completely cooled, transfer the meringues to an airtight container and store at room temperature for up to one week.