Start by washing and removing the stems from 1 pound of fresh strawberries. Next, process the strawberries in a blender or food processor until they form a smooth purée. Next, simmer the puree in a saucepan over medium-low heat, stirring occasionally, until it reduces to about 1/2 cup (135g). This will take around 25–35 minutes. Once reduced, allow the strawberry puree to cool completely before adding it to the cake batter.

Preheat your oven to 350°F (177°C). Grease two 9-inch round cake pans, line them with parchment paper, and grease the parchment paper for easy removal after baking.

In a bowl, whisk together the flour, baking powder, baking soda, and salt. In a separate large mixing bowl, beat softened butter and granulated sugar together at high speed for about 2 minutes until light and fluffy. Add the egg whites and mix until fully combined, then stir in the sour cream and vanilla extract. Gradually add the dry ingredients to the wet mixture, alternating with the milk, and mix until just combined. Gently fold in the strawberry puree, and if desired, a drop or two of food coloring for a more vibrant hue.

Divide the batter evenly between the prepared pans and bake for 24–25 minutes, or until a toothpick inserted in the center comes out clean. Allow the cakes to cool in the pans for about 10 minutes, then gently remove them and place them on wire racks to cool fully.

To make the frosting, process freeze-dried strawberries into a fine powder using a food processor. In a large bowl, beat the cream cheese until smooth, then gradually add softened butter and mix until creamy. Add the powdered sugar, strawberry powder, vanilla extract, and 1 tablespoon of milk, beating until smooth. Adjust consistency by adding more milk if needed, and taste to add salt if desired.

Once the cakes have cooled, level the tops with a serrated knife for a flat surface. Spread a generous amount of frosting over the first cake layer, then top it with the second layer. Frost the entire surface of the cake with the remaining frosting. Refrigerate the cake for at least 45 minutes before slicing to help it hold its shape when cut.