Make the marshmallows:

Cup of Yum
1. In a small bowl, sift together the icing sugar and cornstarch. Set aside.
2. Prepare a 9" by 13" baking sheet with parchment paper. Dust the parchment paper with a layer of icing sugar mixture.
3. In a stand mixer bowl fitted with a whisk, add in the cold water, vanilla extract and gelatin. Let it bloom.
4. In a small saucepan, add in the ¼ C water and granulated sugar. Without stirring the pot, heat until the mixture reaches 240°F/116°C.
5. The sugar syrup will quickly reach 220°F/104°C and then slowly reach 240°F/116°C. Be patient.
6. When the syrup reaches 240°F/116°C, carefully remove from heat.
7. With the stand mixer running on low, gradually pour in the sugar syrup down the side of the bowl.
8. Slowly increase the speed and whisk until the mixture is light and fluffy. It will take about 10-15 minutes. The mixture will turn white and pale.
9. Transfer the marshmallow mixture to the baking tray and smooth out the top with an offset spatula.
10. Dust the top with the remaining icing sugar mixture.
11. Leave to air dry for at least 4-6 hours. When you press your finger gently onto the marshmallow, it should be firm.
12. Dust a small cookie cutter (2.5") with icing sugar/cornstarch and cut out 6 marshmallow rounds (you will have extra marshmallow). Set aside on a large piece of parchment paper.

Make the matcha cake:

1. Preheat oven to 350°F/177°C.
2. Line a 9″ by 13″ baking sheet with parchment paper.
3. In a medium bowl, add egg yolks, 1 tablespoon sugar and beat with a whisk until lightened in colour.
4. Add in the matcha, vanilla extract, milk, avocado oil and whisk to combine.
5. Sift in the cake flour and mix until just combined. Set aside.
6. In a clean stand mixer bowl fitted with a whisk attachment, add the egg whites and whisk on low-medium speed. When it becomes foamy, add in the cream of tartar.
7. Slowly increase the speed and gradually add in the 2 tablespoon sugar. Keep whisking until stiff peaks.
8. Fold about ⅓ of the egg whites into the flour mixture to lighten.
9. Fold in the remaining egg whites into the flour mixture, until there is no white streaks remaining, but being careful not to deflate too much of the batter.
10. Transfer the batter to the prepared baking sheet and smooth out the top using an offset spatula. Drop the pan from a height of 1' to release any trapped air bubbles.
11. Bake at 350°F/177°C for 12-14 mins, or until the cake is springy to the touch.
12. Remove cake from the oven and drop the pan from a height of 1' to prevent the cake from shrinkage.
13. Let cool on a cooling rack for about 20 minutes.
14. Use a small 2.5" cookie cutter to cut out rounds. You should end up with 12 rounds.

Make the chocolate glaze:

1. In a microwave-safe measuring cup, add in the chocolate and coconut oil.
2. Heat in 20-second increments until the chocolate is melted.
3. Stir until the chocolate is smooth.

Assemble:

1. Lay out the cake rounds onto a baking sheet, pairing 2 cake rounds together and placing a marshmallow in the middle to create a "sandwich." You will end up with 6 sandwiches.
2. Chill the sandwiches in the fridge for 20 minutes.
3. Line a large 12" by 17" baking sheet with parchment paper. Place a cooling rack on top.
4. Line up the cookie sandwiches on the cooling rack and pour the warmed chocolate over top of each sandwich.
5. Taking one choco pie at at time, use an offset spatula to carefully dip the bottom of the choco pie onto the excess chocolate (that dripped onto the parchment sheet).
6. Transfer onto a small 9" by 13" baking sheet lined with parchment paper. Place into the fridge for the chocolate to set.
7. You will have to work in batches, scraping the chocolate from the parchment paper back into the measuring cup and re-pouring it over the rest of the choco pies.
8. Repeat with the remainder.