01 - Preheat oven to 350°F. Grease a 9x13-inch baking pan thoroughly.
02 - Whisk together strawberry cake mix, eggs, vegetable oil, and water in a large bowl until just combined. Pour batter evenly into prepared pan.
03 - Beat cream cheese and butter until smooth. Add powdered sugar and vanilla extract; continue beating until mixture reaches creamy, fluffy consistency.
04 - Drop spoonfuls of cream cheese mixture randomly over the surface of the cake batter.
05 - Sprinkle diced strawberries and white chocolate chips evenly over the top. Add shredded coconut if using.
06 - Run a butter knife gently through the batter and cream cheese mixture to swirl together for marbled appearance.
07 - Bake for 40-45 minutes until edges are set but center remains slightly wobbly. The cake should be gooey inside, not overbaked.
08 - Allow cake to cool in pan for at least 30 minutes before slicing and serving.