Dark Chocolate Cupcakes
To make the dark chocolate cupcakes, set a rack in the middle of the oven and preheat to 325° F. Line a standard 12-cup muffin tin with paper cupcake liners.
In a large bowl, whisk together the dry ingredients.
In a second large bowl, whisk together the wet ingredients until no streaks of egg yolk remain.
Combine wet and dry ingredients and mix with a rubber spatula until just smooth and no dry pockets remain.
Fill each cupcake liner about ⅔ full. Bake, rotating pan back to front halfway through baking, 16-19 minutes, until a toothpick inserted into the middle comes out with just a few most crumbs attached.
Let cool slightly, then transfer to a cooling rack and let cool completely while preparing the frosting.
Chocolate Matcha Frosting
To make the chocolate matcha frosting, add ingredients to the bowl of a stand mixer and beat on low until combined, then increase speed to medium-high and beat until frosting is light and fluffy.
Transfer to a large piping bag fitted with a straight tip, or a zip-top bag with one corner snipped off.
Moss Cookie Crunchies
To make the moss cookie crunchies, crush the wafer cookies until they reach the texture of fine sand, using a food processer or bag with a rolling pin.
Transfer the crushed cookies to a large mixing bowl and add the brown sugar and matcha powder. Toss until well mixed.
Add the melted butter and mix, using your hands, until the crumbs are evenly moistened.
Frost the cupcakes by piping an even, generous layer of frosting on top of each. Working with one cupcake at a time, insert the cupcake and gently press the frosted top into the bowl of moss cookie crunchies, rotating so the moss sticks to the sides of the frosting, until the top is evenly coated.
