To Make the Sponge Cake:

When you’re ready to bake the cake, preheat the oven to 400°F. Oil a 12 x 17-inch baking sheet and line with parchment paper on all sides as well as the bottom. Oil the top of the paper, too; set aside.

To a small bowl, whisk together the flour blend, green tea matcha powder, baking powder, and salt.

Add the hot coconut milk to a large mixing bowl. (Don’t use your only stand mixing bowl. You’ll need that to whip the egg whites in a large bowl as well.)

Beat in the sugar all at once until the sugar breaks down, about 2 minutes.

In the bowl of your stand mixer or a handheld mixer fitted with the whisk attachment, beat the egg whites until foamy on medium speed, about 1 minute. Add the cream of tartar and beat on high speed until stiff but moist peaks form. (It should look like foamy shaving cream and when you lift the whisk attachment, you should see a stiff curled peak.)

Fold the egg whites in three separate portions into the cake batter until no white streak remain before adding another third.

Fold in the pistachio nuts gently using a silicone/rubber spatula.

Transfer the batter to the prepared baking pan and evenly distribute.

Bake on the center shelf for 15 minutes or until the center of the cake does not leave an indention when lightly touched using a silicone spatula or your fingertips.

Remove the cake from the oven and transfer to a wire rack. Oil another wire rack or baking sheet. Place the oiled wire rack on top of the cake and invert. Remove the original rack and the parchment paper.

Allow the cake to cool for 15 minutes.

Trim 1/16-inch off of all four sides of the cake. You’ll end up with about a 15-1/2 x 9-1/2-inch cake. Using a serrated knife, slice the cake into three sections, each 9-1/2 x 5-1/4-inch. Set aside.

To Make the Italian Buttercream:

Make the buttercream as instructed at the above recipe link with the following difference: When adding the sugar, also add 1/2 teaspoon green tea matcha powder and replace half of the vanilla extract with almond extract. (Later, you can add more to the mixer to darken the color if desired.)

For the Chocolate Ganache:

Make half a recipe of ganache using semi-sweet or bittersweet chocolate; set aside to cool and thicken. (You’ll have leftovers you can use for other desserts or to top ice cream.)

To Assemble and Decorate the Cake:

Evenly frost one layer with buttercream.

Lay the second cake layer on top and frost with chocolate ganache that is cool enough to be spreadable.

Top with the last cake layer and frost with more buttercream. Refrigerate until completely set and cold, up to 4 hours or more.

To Make the White Chocolate Ganache:

Make half a recipe of ganche using the tips section of that recipe for white chocolate and adding a little matcha for color as desired. (You’ll have leftovers you can use for other desserts or to top ice cream.) It’s great in coffee too if you enjoy milk and sweetener!

Finally, be sure the white ganache is a pourable texture, but not hot. If it’s not runny enough, microwave it a tiny bit. It can’t be too hot or it will melt the buttercream. Then, top the cake with the green tea white ganche.

Allow to completely set or refrigerate to speed up the process. This cake may be frozen for months or refrigerated up to three days and served no later than the third day.

Allow the cake to reach room temperature, slice into squares, and serve.