Preheat oven to 350 degrees F (175 degrees C). Line muffin tins with paper cups.
In a medium bowl, beat the cream cheese, egg, 1/3 cup sugar and 1/8 teaspoon salt until light and fluffy. Stir in white chocolate chips and set aside.
In a large bowl, mix together the flour, 1 cup sugar, baking soda and 1/2 teaspoon salt. Make a well in the center and add the water, oil, and vanilla. Stir together until well blended. Fill muffin tins 1/3 full with the batter and top with a tablespoon of the cream cheese mixture.