Three layers of honey matcha cake filled with sweetened red bean paste and lightly coated with matcha buttercream.
Yield: 8-inch layer cake
Preheat oven to 350 degrees F. Lightly grease three 8-inch round cake pans and line with parchment paper. Set aside.
In the bowl of a stand mixer fitted with a paddle attachment, cream butter. Add sugar and mix until incorporated. Add sifted matcha powder and mix until combined. Scrape down bowl as needed to ensure thorough mixing.
Add honey. Add eggs one a time, mixing on low speed until incorporated.
In a large bowl, whisk together flour, salt, and baking powder. Add flour mixture in three additions, alternating with buttermilk. Start and end with flour mixture. Mix until just combined. Be careful not to overmix.
Divide cake batter among the prepared cake pans. Level batter, if necessary. Bake for 30-35 minutes until toothpick inserted in center of cake comes out clean. Allow cake to cool in pan for 3-5 minutes before unmolding. Allow cakes to cool to room temperature on wire racks.
In the bowl of a stand mixer fitted with a paddle attachment (or using a hand mixer), cream butter until smooth. Sift together powdered sugar and matcha powder. Add to bowl in three additions. Mix on low speed after each addition. Add salt and milk. Mix until combined. Adjust consistency according to your personal preference. If buttercream is too thick, add milk 1 Tbsp at a time until desired consistency is achieved. If buttercream is too thin, add 1/4 cup sifted powdered sugar (up to 3/4 cup). Set aside until ready to use.
Place sweetened red beans in a small bowl. Coarsely mash some of the red beans with a fork or the back of a spoon. Set aside.
Level cake rounds, if necessary. Place one cake layer on serving plate or cake stand. Spread a very thin layer of matcha buttercream over cake. Pipe a border of matcha buttercream along the perimeter of cake. Spread half of red bean paste within the buttercream border. Repeat with second cake round. Top with third cake round. Spread thin layer of buttercream around the exterior of cake to seal in any crumbs.
Keep chilled in the fridge until ready to serve. Allow cake to sit at room temperature for 15-20 minutes before serving to soften. Before serving, dust the top of cake with sifted matcha powder. If desired, decorate the cake with meringue cookies*.