Preheat oven to 350 degrees. In a medium mixing bowl with an electric mixer, beat cream cheese, egg, 1/3 cup sugar and salt. Stir in chocolate morsels; set aside.
In a large mixing bowl add flour. cocoa, and remaining 1 cup of sugar and baking soda. Add water, oil, vinegar, and vanilla. Beat until well mixed.
Fill 24 greased or paper-lined muffin cups one-third full with chocolate batter. Top each with a heaping spoonful of cream cheese mixture. Sprinkle with additional sugar, if desired. Bake fro 30 to 35 minutes, or until done.
Makes 24 cup cakes