Step 1

Preheat oven to 350°F.

Step 2

Whisk together the first 4 ingredients in a large mixing bowl. In a four-cup measure, stir together the sour cream, water, and eggs. With a hand mixer running on low speed, gradually pour the liquid ingredients into the dry ingredients. Scrape the bowl down and mix again until all ingredients are consistently incorporated. Divide the cake batter into two mixing bowls. To one bowl add the three tablespoons wild strawberry compound and mix well by hand (also add the optional red food color, if desired). To the other bowl, add the lemon verbena swirl and mix well by hand (also add the optional yellow food color, if desired). Divide the wild strawberry batter between two pans; divide the lemon verbena batter between the remaining two pans.

Step 3

Bake the cakes for 30-35 minutes, or until they spring back when pressed in their centers. Let cool in the pans 5 minutes; turn out on wire racks to cool completely. Level cakes using a cake leveler or serrated knife.

Step 4

Set a saucepan filled one-third full of water over medium-high heat and bring to a simmer.

Step 5

Whisk together the egg whites, sugar, and salt in a large heatproof bowl (I suggest a stainless bowl). Set over the simmering water and whisk until the mixture is hot to the touch and the sugar has dissolved (120-140 degrees on a candy thermometer, to be sure).

Step 6

Transfer the mixture to the bowl of a stand mixer fitted with the whisk attachment.

Step 7

Beat on medium speed for 2 minutes. Increase to medium-high until stiff peaks are formed.

Step 8

Continue beating at medium-high speed until the mixture is fluffy and has cooled (the mixing bowl should feel cool to the touch).

Step 9

Turn the mixer off and switch from the whisk attachment to the paddle. Turn the mixer on medium-low and add the butter, a few cubes at a time, beating until well incorporated before the next addition. The mixture will deflate with the butter addition, this is normal – keep going – adding butter a little at a time. When all of the butter is incorporated, increase the speed to high and beat until thick and smooth. Add the lemon flavoring and beat again until incorporated.

Step 10

Frost the cake: Place a lemon verbena layer on a cake plate. Top it with approximately 1/2 cup of lemon buttercream and spread evenly. Center a wild strawberry cake layer on top of the frosting and top with 1/2 cup lemon buttercream; Repeat this process with the remaining lemon verbena layer and end with the final wild strawberry layer on top. Use the remaining frosting to cover the outside of the cake. Smooth using a cake smoother or an offset spatula. Refrigerate the cake until the frosting is firm, about 25 minutes.

Step 11

Melt chocolate in the microwave at 30 second intervals; stir until smooth. Turn a cookie sheet upside-down and pour on the chocolate. Spread evenly with an offset spatula. Place in the refrigerator for 5-7 minutes, or until the chocolate is firm and has a matte appearance.

Step 12

Remove from refrigerator and let stand for a few minutes (3-5ish) at room temperature. With a small, sharp spatula, begin scraping chocolate at one edge in a thin strip. If chocolate breaks into pieces it is too cold, so allow it to stand a few minutes more at room temp. Chocolate should curl easily as you run your spatula under the chocolate and down the length of the cookie sheet. Place curls in a small bowl and store in refrigerator until ready for use. Chocolate melts at body temperature, so handle them as little as possible. If you have particularly hot hands, use a spoon to transfer the curls to the top of the cake.

Step 13

Garnish cake with chocolate curls, whole strawberries with stems and food safe flowers. Bring the cake to room temperature before serving. Keep leftovers in the refrigerator loosely covered with plastic wrap.