Get a 9-inch pan with parchment paper and dust a mixture of powdered sugar and cornstarch.

Whisk aquafaba and cream of tartar until soft peaks form (about 10 minutes)

On a medium-high flame, mix granulated sugar and water to prepare the syrup.

Simmer without stirring until the syrup reaches 240°F.

After removing the syrup from the heat, slowly pour it into the aquafaba while whisking.

Whisk for about 5 minutes until glossy, with stiff peaks.

Add vanilla extract.

In another saucepan over medium-high heat, whisk together granulated sugar, water, and agar-agar powder (to make vegan gelatin mixture)

Boil and whisk continuously for 2 to 3 minutes.

Turn on the mixer and slowly pour the agar mixture into the aquafaba.

Whisk until the agar is fully mixed.

Pour the marshmallow mix into the pan, spreading evenly.

Cover loosely with a kitchen towel and cool for 4 to 6 hours, or until set.

Once set, dust the tops with a mix of powdered sugar and cornstarch.

Cut the vegan marshmallows into your preferred shapes.