Line a baking sheet with parchment paper and evenly dust it with 1 tablespoon of arrowroot powder.

In your stand mixer bowl fitted with the whisk attachment (or a large bowl if using a handheld mixer), pour in ½ cup of water and sprinkle the gelatin over the top. Let it sit for 10 minutes to bloom.

While the gelatin blooms, combine the remaining ½ cup of water with the honey in a saucepan. Heat over medium-high heat until it reaches 240°F on a candy thermometer, about 15 minutes.

With the mixer on low speed, slowly pour the hot honey mixture into the bowl. Add the vanilla extract and matcha powder. Increase the speed to medium-high and whip for 8–10 minutes, until the mixture is light green and has tripled in volume.

Pour the mixture onto the prepared baking sheet and smooth it out quickly with an offset spatula. Let it set at room temperature for 6 hours.

Dust the top with another tablespoon of arrowroot powder. Using a sharp knife lightly greased with coconut oil, cut into 24 pieces. If the marshmallows are sticky, gently coat them with the remaining arrowroot powder.