Prepare the reduction preferably a day before baking the cake.

Combine fresh or thawed strawberries in a medium saucepan. Optionally, blend for a smoother texture.

Heat over medium-high, adding sugar (if desired), lemon zest, juice, and salt. Stir occasionally to prevent scorching.

Once boiling, lower heat and simmer until mixture is reduced by half, about 20 minutes. Continue cooking if still watery until thickened.

Stir periodically to prevent sticking. Aim for approximately 2 cups of thick reduction. Cool before use. Store excess in the refrigerator for up to a week or freeze for six months.

Ensure all ingredients are at room temperature.

Remove strawberry reduction from the refrigerator an hour before baking.

Preheat oven to 350ºF/176ºC and position a rack in the middle.

Grease three 8" cake pans.

Whisk together milk, strawberry reduction, emulsions, extracts, lemon zest and juice, and food coloring.

In another bowl, whisk flour, baking powder, baking soda, and salt.

Beat butter in a stand mixer until smooth, then gradually add sugar and beat until fluffy.

Add egg whites gradually, beating well after each addition.

Alternately add dry ingredients and milk mixture to the batter in thirds, mixing until just blended.

Divide batter evenly among pans and smooth tops.

Bake until firm and a toothpick inserted comes out clean, about 30-35 minutes.

Cool in pans on a wire rack for 10 minutes, then unmold and cool completely. Wrap and refrigerate or freeze before assembling.

Combine egg whites and powdered sugar in a stand mixer, whip on high for 5 minutes.

Add butter in chunks, whipping until light and fluffy.

Incorporate strawberry reduction, vanilla extract, and salt.

Optional: Switch to a paddle attachment and mix on low for 15-20 minutes to smooth out the buttercream.

Trim the top of the first cake layer to level, if necessary.

Apply a thin layer of cooled reduction to the cake surface.

Spread a layer of strawberry buttercream.

Repeat layering with remaining cake rounds and frosting.

Frost the outside of the cake and garnish with fresh strawberries, if desired.