01 - Preheat oven to 350°F. Grease a 9x13-inch baking pan thoroughly with cooking spray or butter.
02 - Combine strawberry cake mix, eggs, oil, and water in a large bowl. Mix according to package directions 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, about 2-3 minutes.
04 - Drop spoonfuls of cream cheese mixture evenly over cake batter. Scatter diced strawberries and white chocolate chips across the top. Sprinkle with shredded coconut if using.
05 - Run a knife gently through the layers to swirl cream cheese mixture into batter, creating a marbled pattern. Do not overmix.
06 - Bake for 40-45 minutes until cake is mostly set but still slightly gooey in center. The center should wiggle slightly when pan is gently shaken.
07 - Let cake cool in pan for at least 30 minutes before slicing. Serve warm or at room temperature.