1 (8 ounce) package cream cheese, softened
1 egg
1/3 cup white sugar
1/8 teaspoon salt
1 cup miniature semisweet chocolate chips
1 1/2 cups all-purpose flour
1 cup white sugar
1/4 cup unsweetened cocoa powder
1 teaspoon baking soda
1/2 teaspoon salt
1 cup water
1/3 cup vegetable oil
1 tablespoon cider vinegar
1 teaspoon vanilla extract

Preheat oven to 350 degrees F (175 degrees C). Line muffin tins with paper cups or lightly spray with non-stick cooking spray.
In a medium bowl, beat the cream cheese, egg, 1/3 cup sugar and 1/8 teaspoon salt until light and fluffy. Stir in the chocolate chips and set aside.
In a large bowl, mix together the flour, 1 cup sugar, cocoa, baking soda and 1/2 teaspoon salt. Make a well in the center and add the water, oil, vinegar and vanilla. Stir together until well blended. Fill muffin tins 1/3 full with the batter and top with a dollop of the cream cheese mixture.
Bake in preheated oven for 25 to 30 minutes.

Source: allrecipes.com