In a large mixing bowl, combine the strawberry cake mix, salt, melted butter, eggs, and vanilla extract. Mix until well combined. Fold in the white chocolate chips if using then spread into the prepared baking pan. Press the mixture evenly into the pan.
1 box strawberry cake mix, 1/4 tsp salt, 1/2 cup unsalted butter, 2 large eggs, 1 teaspoon vanilla extract, 1/2 cup white chocolate chips