Make the reduced strawberry puree first, and let cool: In a blender or food processor, puree the fresh strawberries. You should have a little over 1 cup (about 270g). Transfer the puree to a small saucepan over medium-low heat. Simmer, stirring occasionally, until it’s reduced to ½ cup (about 135g). This usually takes around 25–35 minutes.

Preheat the oven to 350°F (177°C). Grease two 9-inch round cake pans, line with parchment paper rounds, then grease the parchment paper.

Make the cake: In a medium bowl, whisk the cake flour, baking powder, baking soda, and salt together. Set aside.

In a large bowl, beat the butter and sugar together on medium-high speed until light and creamy, about 3 minutes. Add the egg whites and beat on high speed until combined. Add the sour cream and vanilla extract and beat until combined. Add the dry ingredients and, with the mixer running on low, slowly pour in the milk and beat until just combined.

Whisk in the room-temperature reduced strawberry puree and food coloring (if using). Pour the batter evenly into the prepared cake pans.

Bake for 24–25 minutes or until a toothpick inserted in the center comes out clean. Cool the cakes in the pans set on a cooling rack for 1 hour.

Make the frosting: In a blender or food processor, process the freeze-dried strawberries into a fine powder. Set aside. In a large bowl, beat the cream cheese and butter on medium-high speed until smooth. Add the confectioners’ sugar, strawberry powder, milk, and vanilla. Beat until combined and creamy.

Assemble and frost: Level the cakes by slicing a thin layer off the tops to create a flat surface. Place 1 cake layer on your cake stand. Spread ¾–1 cup of frosting on top. Top with the second layer, upside down, and spread 1 cup of frosting all over to make a crumb coat. Refrigerate until the crumb coat sets, about 20 minutes.

Cover the top and sides with the remaining frosting and refrigerate for at least 20 minutes before slicing.