01 - Preheat oven to 350°F. Grease a 9x13-inch baking dish thoroughly with cooking spray or butter.
02 - In a large bowl, combine the strawberry cake mix, eggs, vegetable oil, and water. Mix with electric beaters or whisk until completely smooth and blended, about 2 minutes. Spread the batter evenly into the prepared baking dish.
03 - In a separate bowl, beat the softened cream cheese and butter together until smooth and creamy, about 2 minutes. Add the powdered sugar and vanilla extract; continue beating until fully combined and fluffy, scraping down the sides as needed.
04 - Drop spoonfuls of the cream cheese mixture randomly over the surface of the cake batter, leaving some spaces of batter visible.
05 - Use a butter knife or skewer to gently swirl the cream cheese mixture through the cake batter. Make figure-eight or circular motions, being careful not to overmix—you want distinct marbled swirls.
06 - Sprinkle the white chocolate chips, chopped strawberries, coconut (if using), and nuts (if using) evenly over the top of the swirled batter.
07 - Bake for 40 to 45 minutes, or until the edges are golden brown and the center is set. A toothpick inserted in the center should come out with a few moist crumbs but not wet batter. Do not overbake.
08 - Let the cake cool in the pan for at least 30 minutes before serving. The cake will be slightly warm and gooey in the center. Serve warm or at room temperature.