Preheat your oven to 350°F (175°C). Grease the baking pan with cooking spray or butter.
In a large mixing bowl, combine the strawberry cake mix, water, vegetable oil, and eggs. Using an electric mixer, blend on medium speed for 2 minutes until well combined.
Gently fold in the chopped strawberries into the cake batter using a rubber spatula.
Pour half of the batter into the prepared baking pan and spread it evenly.
In another bowl, beat the softened cream cheese, powdered sugar, milk, and vanilla extract together until smooth.
Spoon the cream cheese mixture evenly over the first layer of cake batter. Use a spatula to spread it out slightly, leaving gaps for the batter to rise around it.
Pour the remaining cake batter over the cream cheese layer, spreading it evenly.
If using, sprinkle the shredded coconut and chopped nuts on top of the batter.
Bake in the preheated oven for 40-45 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool in the pan for about 15 minutes, then slice and serve warm or at room temperature.