01 - Preheat oven to 350°F. Grease a 9x13-inch baking pan thoroughly.
02 - Combine strawberry cake mix, eggs, oil, and water in a large bowl. Mix until smooth. Pour batter evenly into prepared pan.
03 - Beat softened cream cheese, butter, powdered sugar, and vanilla extract in a separate bowl until smooth and creamy.
04 - Drop spoonfuls of cream cheese mixture evenly over cake batter. Scatter diced strawberries and white chocolate chips across top. Sprinkle with coconut if using.
05 - Gently swirl cream cheese mixture into cake batter using a knife to create marbled pattern.
06 - Bake 40-45 minutes until mostly set but slightly gooey in center. Do not overbake.
07 - Cool in pan at least 30 minutes before slicing and serving.