Mix cake mix according to package directions. Place 24 paper cups in cupcake pan. Fill each cup 2/3rds full with cake batter.
Cream together cream cheese, sugar, egg and salt; stir in chocolate chips.
Drop teaspoons of cheese mixture into center of cake batter of each cupcake. Divide cream cheese mixture among 24 cupcakes.
Bake as directed for cupcakes on cake box directions. Remove from oven and allow to cool.