Preheat the oven to 100°C (212°F).
Place the egg whites in a bowl and beat them until stiff peaks form.
Add erythritol in 2 to 3 portions while continuing to whip.
Once the meringue is completely firm, add vanilla extract and whip lightly again.
Transfer the meringue to a piping bag and pipe small circles onto a baking sheet.
Bake in the preheated oven for 70 to 90 minutes.
Let them cool completely before storing.