I was mostly inspired to make this because I wanted to make a really woody and vibrant-green dessert. Mostly because with St. Patrick’s Day coming up, I had to get together as many green, Irish, beer, or gold-themed dessert ideas together as possible. So this would be one of them. For my components, we have a matcha chiffon cake that has roasted chestnuts folded into it, chestnut-cacao yokan(Japanese jelly that is typically made with bean paste), matcha mousse, chestnut ganache, matcha mirror glaze, and tempered matcha disks. There’s a ton of components, and this wound up being a two-day process when I made it, but I guarantee you that it’s well worth the wait!

For the chestnut ganache:
1 teaspoon gelatin powder
1 tablespoon water
25g heavy cream
a pinch of salt
50g chestnut puree
25g white chocolate

In a pot, mix the gelatin with water. Then pour into that your cream and salt and bring to a low simmer, stirring to make sure that the gelatin is fully melted into the cream without sticking and burning to the bottom of your pot. Once the gelatin is dissolved, stir in the remaining ingredients on low heat until fully incorporated. Pour the mixture into a 4 inch by 4 inch square mold and freeze solid. You want this to be a literal ice block before using.

For the chestnut-cacao yokan:
50g chestnut puree
2 tablespoons agar agar
1 teaspoon black cacao powder
a pinch of salt
1 teaspoon granulated sugar
3 tablespoons water

Mix ingredients together in a pot over low heat, stirring constantly, until they form into a paste-like consistency. Pour the paste into 1-inch silicone half-dome molds, tapping the molds to remove any excess air bubbles. You should have 7 spheres. Smooth off the tops with an offset spatula and freeze until set, at least 2 hours. With 4 of these spheres, you want to cut them in half, then keep them frozen for the assembly. The remaining 3 will be used on top for garnish.

For the chestnut-matcha sponge:
4 egg whites
2 egg yolks
a pinch of salt
1/2 cup granulated sugar
1/2 teaspoon baking powder
3 tablespoons canola oil
1 teaspoon matcha powder
1 teaspoon vanilla extract
2/3 cups all-purpose flour
1/4 cup chopped chestnuts

Whip your egg whites with the salt, half of the sugar, and baking powder. Whip the egg yolks with the remaining sugar, matcha, canola oil, and vanilla. Sift the flour to remove lumps, then toss the chestnuts into the flour. Once your have stiff egg whites, fold your three ingredients together. Pour and spread onto a lined sheet tray. Bake at 350 degrees F for 18 minutes. Allow the cake to cool before cutting out two 6-inch by 6-inch squares.

For the soak:
1/4 cup hot water
1/2 teaspoon matcha powder
a pinch of salt
1/4 cup milk

Whisk water with matcha and salt until frothy and free of lumps. Whisk into that the milk.

For the matcha mousse:
2 teaspoons gelatin powder
2 tablespoons cold water
1/4 cup milk
2 egg yolks
3 tablespoons granulated sugar
a pinch of salt
1/4 teaspoon spirulina powder
2 teaspoons matcha powder
1 teaspoon vanilla extract
2/3 cups heavy cream

Mix the gelatin with cold water in a pot. Mix into that your milk and heat up, allowing the gelatin to dissolve into the milk. Whisk the egg yolks with salt and sugar and then temper into that your milk. Whisk the egg yolks with the milk in a pot for 2 minutes on medium heat, then take off heat. Whisk into that your matcha, spirulina, and vanilla. Pass through a sieve and allow it to cool down. Whip heavy cream to stiff peaks. Fold that into the egg yolk mixture. Line a 6-inch by 6-inch square mold with acetate. Place one piece of cake down first, then add in half of your soak. Place on the bottom your halved yokan spheres and then pour in half of your mousse. Press into that the frozen chestnut ganache square. Then pour in about 80% of your remaining mousse, then the second soaked cake layer, then the remainder of the mousse. Spread the mousse evenly over the second layer so that it will guarantee even glazing when it comes time to finish. Freeze, at least 4 hours, until solid before attempting to unmold and glaze.

For the mirror glaze:
2 packets gelatin powder
1/4 cup cold water
1/4 cup hot water
1/4 cup milk
a pinch of salt
1 teaspoon matcha powder
1/2 teaspoon spirulina powder
1 cup white chocolate chips

Mix gelatin with cold water. Place the gelatin into a pot with hot water and milk and bring to a simmer. Take off heat and then stir in the matcha, spirulina, salt, and white chocolate, using a rubber spatula. Do not use a whisk, or you will incorporate air into the glaze. Pour through a sieve to remove lumps. Pour the glaze, heated to 90 degrees F, over the still-frozen mousse cake, which you should have placed on an elevated surface, such as on a measuring cup, can, deli cup, or ring mold. Allow your glaze to sit for at least 5 minutes before attempting to move the cake to a serving surface to finish.

For the tempered disks:
1/2 cup white chocolate chips
a pinch of salt
1/4 teaspoon matcha powder

Heat the white chocolate with salt in a double boiler until half-melted. Take off heat and stir until the remainder of the chocolate has melted and the mixture registers 88 degrees F. Pour half of the mixture onto acetate and spread using a combed bench scraper. Mix the remainder of the melted chocolate with matcha. Allow the white chocolate on the acetate to sit for at least 2 minutes while doing this. Pour the matcha chocolate onto the acetate and spread it on using an offset spatula. Allow the chocolate to refrigerate for 1 1/2 minutes, then press out circle shapes using cookie cutters, before returning the acetate to the refrigerator for another 10 minutes before attempting to unmold.

To finish:
Roasted chestnuts

Place roasted chestnuts, the un-cut yokan, and the disks on top of your set cake to finish.