Step 1

Heat the oven to 110C (90C fan)/230F/gas ¼.

Step 2

Line two oven sheets with baking paper or a reusable baking mat, and get ready a piping bag with a roughly 1⅓cm nozzle, if you have one.

Step 3

Pour the aquafaba into the bowl of a stand mixer, or a large, scrupulously clean glass or ceramic bowl anchored to a work surface with a damp cloth or similar.

Step 4

Begin to whisk on a medium-high speed until foamy, add the cream of tartar, if using and whisk to firm peaks (depending on the make of your stand mixer, you might need to get in there with a hand mixer at the beginning, because liquid can get trapped in the bottom in some models when working with relatively small volumes).

Step 5

Reduce the speed slightly and very gradually add the caster sugar spoonful by spoonful, giving each addition time to be absorbed before adding the next. Add a pinch of salt and the vanilla extract or other flavouring, if using.

Step 6

Turn up the speed again and whisk until the mixture forms firm, glossy peaks and is stiff enough for you to tip the bowl without it moving (this will take longer than it does with egg whites), then use a large metal spoon to fold in the sifted icing sugar a third at a time, being careful to keep as much of the air in the mix as possible.

Step 7

Transfer the meringue mix to the piping bag (or similar), then pipe or spoon on to the lined trays in roughly 5cm rounds spaced slightly apart (or make shapes of your choice).

Step 8

Bake for about two hours, by which point the meringues should be completely dry and lift easily off the sheets. (Note that larger shapes will take longer to get to this point, so adjust the timings accordingly.)

Step 9

If you’d like your meringues really crisp, turn off the oven and leave them in there to cool down; otherwise, take them out and leave in a dry place to cool on the trays. Eat as soon as possible.