Preheat the oven to 350°F. Heat the oven to the right temperature so the cake bakes evenly.
Line three 8-inch cake pans with parchment paper. Put paper in the pans so the cake doesn't stick and is easy to remove.
Grease and flour the pan sides. Smear butter or oil on the pans and add flour to prevent sticking and give a smooth finish.
Puree fresh strawberries in a food processor or electric blender. Crush strawberries to spread the flavor throughout the cake.
Mix flour, baking soda and salt in a separate bowl. Combine these dry ingredients to strengthen the cake structure.
Beat butter and sugar through electric mixer until light and fluffy. Mix the fats and sugars to incorporate air for a soft texture.
Add egg yolks one at a time, then vanilla. Mix in the yolks and vanilla for color, flavor and moisture
Alternately add flour mix and buttermilk, beating well after each. Slowly mix wet and dry ingredients thoroughly for a smooth batter.
Beat egg whites until peaks form. Whip the whites to add lift and hold the cake's shape as it bakes.
Gently fold egg whites into batter. Fold the whites in gently so they don't deflate and can help the cake rise.
Divide the batter in half and add red food coloring and crushed berries to one half. Separate the batter to swirl two colors together for the marble effect.
Pour batters alternately into pans to create marble pattern. Drop spoonfuls of each color batter into pans to get red and white swirls.
Bake for 30 minutes or until a toothpick comes out clean. Cook the cake through completely.
Cool for 15 minutes before removing from pans to wire racks to cool completely. Let the cake gradually cool so it sets properly without becoming soggy.
Mix cream cheese frosting ingredients with a few drops red food coloring. Prepare a light, fluffy frosting to match the cake and spread on top and sides.
Frost the layers and decorate with fresh strawberries for color, flavor and presentation. Assemble and decorate the finished cake.