Open the chilled cans of coconut milk and scoop out the solid cream, leaving the liquid behind.
In a large bowl, whip the coconut cream with powdered sugar (or maple syrup) and vanilla extract until smooth and fluffy.
In a small saucepan, combine agar-agar powder and ¼ cup water. Bring to a boil, stirring constantly, then simmer for 1-2 minutes until the agar-agar is dissolved.
Gradually fold the agar-agar mixture into the whipped coconut cream until fully incorporated.