Preheat your oven to 220 F (100 C).
Separate the egg whites from the yolks using your preferred method. We usually use the method of passing the egg yolk between two halves of the shell until the egg white falls into a bowl below. Save the egg yolks for a different recipe! It's important that no egg yolk get in the bowl of egg white, as this could prevent the meringue from whipping properly.
In the bowl of a stand mixer (a totally clean bowl, with no oil/residue anywhere, as this could affect the egg whites whipping properly as well) with the whisk attachment, add your egg whites and a splash of lemon juice (you can also use some cream of tartar as the stabilizer instead). Start whipping until your egg whites look frothy.
Add in your vanilla extract. Slowly add your sugar one tablespoon at a time while the mixer is running. If you add it too quickly, the sugar will not dissolve and it will end up grainy!
Make sure to scrape down the sides of the bowl occasionally, so there are no sugar crystals around the edge.
Once all the sugar has been added, keep whisking until you have reached stiff peaks - this can take a little while! Note: if your mixture is underwhipped, it will remain liquidy, but not split. If your mixture ever splits or separates or looks curdled, you have likely overmixed your egg whites, and there is no coming back from that - start over with new eggs!
Once the mixture has reached stiff peaks, prepare a baking sheet with parchment paper. Add a little meringue underneath each corner of the paper to stick it to the baking sheet for easier pavlova shaping!
Divide the meringue into 4, 6, or 8 even portions on your baking sheet.
Using a palette knife or a butter knife, build up the sides a little higher than the middle so you have a bit of a well for your filling to go into.
We also like to swirl a palette knife along the edges of the meringues to make a wavy pattern!
Once you're happy with the shape of the pavlovas, bake for 90 minutes on the center rack. If the edges are solidly set and crispy on the outside, you can turn off the oven! In an ideal world, you wouldn't open the oven at all as this can cause the meringue to crack or fall. Leave the pavlovas in the oven to cool down slowly for at least one hour, preferably 2.
After a few hours, crack open the oven door and let them cool for another 30 minutes to an hour with the door open.
Take the pavlova out of the oven. You may experience cracking along the top of the ridges/edges that were built up, but if the sides are crispy and baked through, it will have the correct marshmallow texture on the inside and crispy edges!