Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking pan or line it with parchment paper.

In a large bowl, combine the chocolate cake mix, water, and eggs. Whisk until smooth and ensure there are no streaks.

Stir in the melted butter until fully incorporated.

Pour half of the batter into the prepared pan, spreading it out evenly.

Layer the sliced strawberries over the batter in a single layer.

In another bowl, beat the softened cream cheese with the powdered sugar until smooth and lump-free.

Drop dollops of the cream cheese mixture across the strawberries.

Spoon the remaining batter over the top to cover.

Sprinkle the chopped walnuts or pecans on the surface.

Bake for 40 to 50 minutes, or until a toothpick inserted in the center comes out clean.

Allow the cake to cool completely in the pan before cutting it into squares.