Start by preparing the cake layers so they have time to cool after baking. Preheat your oven to 350°F (175°C) and prepare three 8-inch or four 7-inch cake pans by greasing them and lining the bottoms with parchment paper (this recipe was tested with 7-inch pans). In a large mixing bowl, combine 2 3/4 cups of cake flour, 2 1/2 cups of granulated sugar, 3 tablespoons of matcha powder, 2 1/2 teaspoons of baking powder, and 1 teaspoon of fine salt. Whisk everything together until the dry ingredients are fully blended.

Cut 1 cup (2 sticks) of unsalted butter into tablespoon-sized pieces and mix it into the dry mixture using a paddle attachment or a hand mixer set to low speed. Keep mixing until the butter is fully incorporated and the mixture resembles coarse, damp sand. Add in 1 cup of egg whites and mix on medium speed until the batter thickens.

Next, add 1 1/2 cups of full-fat sour cream, 2 tablespoons of vegetable oil, and 1 teaspoon of vanilla extract to the bowl. If you want to boost the green color of your cake, add a small drop of electric green gel food coloring at this stage. Mix on low speed until everything is incorporated, then scrape down the sides and bottom of the bowl using a rubber spatula. After that, beat the batter on medium speed for about 30 seconds to ensure it's smooth and well combined—this reverse creaming method helps produce a tender crumb.

Evenly divide the batter between your prepared pans and bake for 33 to 36 minutes, or until a toothpick inserted into the center comes out with just a few moist crumbs. Allow the cakes to cool in their pans for 10 minutes before gently running an offset spatula around the edges to loosen them. Flip the cakes out onto a wire rack to cool completely. Once they’re cooled, level the tops with a serrated knife if needed. If baking ahead of time, you can freeze the cake layers and then let them sit at room temperature for about 20 minutes before assembly. They should still be cold to the touch when you begin assembling the cake, which makes stacking and frosting easier.

While the cake layers are baking and cooling, prepare the strawberry Swiss meringue buttercream. It’s important to start with a clean, grease-free mixing bowl—any residue can prevent the meringue from whipping properly. In a medium pot, bring about 1 inch of water to a simmer. Combine 8 egg whites and 2 1/2 cups of granulated sugar in a large metal mixing bowl and place it over the pot to create a double boiler. Make sure the water doesn’t touch the bottom of the bowl.

Constantly whisk the egg white and sugar mixture for about 3 minutes, or until it reaches a temperature of 160°F (71°C). You’ll know it’s ready if the sugar is completely dissolved and the mixture feels hot and smooth when rubbed between your fingers. Remove the bowl from the pot, wipe the bottom dry, and transfer the mixture to the bowl of a stand mixer. Whisk on medium-high speed for around 10 minutes, or until stiff, glossy peaks form.

Reduce the mixer speed to medium and add 2 cups of unsalted butter one stick at a time. The frosting will gradually come together into a thick, whipped consistency. If it appears curdled or broken, continue mixing—it should smooth out within 10 more minutes. If problems persist, refer to a Swiss meringue troubleshooting guide. Once the butter is fully incorporated, add 1/2 cup of strawberry jam, 1 tablespoon of freshly squeezed lemon juice, 1 teaspoon of vanilla extract, and 1/2 teaspoon of fine salt. Mix until fully combined, then add 1/2 cup of freeze-dried strawberry powder for additional flavor and color. Scrape down the bowl as needed. For a brighter pink hue, mix in a drop of red gel food coloring.

To create an ultra-smooth frosting texture, switch to a paddle attachment and mix on low speed for a couple more minutes. Transfer half of the frosting into a large piping bag and snip a 1-inch opening at the tip. Set aside until ready to assemble.

To begin assembling, place your first cake layer onto a greaseproof cake board or flat plate, using a small amount of frosting to secure it in place. Spread a thin layer of strawberry buttercream across the top. Pipe a thick ring of buttercream around the edge of the cake to act as a barrier, then fill the center with about 1/2 cup of strawberry jam. If serving the cake the same day, you can also add a handful of chopped fresh strawberries for extra texture. Repeat the process with the remaining cake layers, flipping the top layer upside down for a flat, clean finish on top.

Place the cake in the freezer for 5 to 10 minutes to firm up the layers and prevent them from sliding. Once chilled, apply a thin crumb coat around the outside of the cake to trap any loose crumbs. Smooth the frosting with a bench scraper, then chill the cake again in the fridge for 30 minutes or in the freezer for 10 minutes, until the frosting is set.

Reserve about 1/3 cup of frosting, and apply a second, thicker layer of buttercream over the entire cake using the remaining frosting. Use a large offset spatula to create a textured effect in the frosting for a rustic, finished look. Take the reserved frosting and tint it with 1 tablespoon of matcha powder and a small drop of electric green gel food coloring. Use a small offset spatula to swipe and blend the green frosting into the pink buttercream, creating a beautiful, ombre-style finish. Slice and serve when ready, and enjoy this elegant and delicious Strawberry Matcha Cake.