Preheat oven to 350°F. Lightly spray a (24 count) mini-muffin pan with vegetable spray.
In a medium mixing bowl, using an electric mixer, blend together the cream cheese, egg, ⅓ cup granulated sugar, and salt until smooth. Using a rubber spatula, fold in the chocolate chips. Set aside.
In a clean medium mixing bowl, combine all the chocolate cake ingredients. Gently blend (using clean beaters or a wooden spoon) until the mixture is smooth and all ingredients are incorporated.
Scoop 1 tablespoon of the chocolate mixture into the wells of the muffin tin. Allow the chocolate "bottoms" to rest for 5 minutes. Scoop 1 teaspoon of the cheesecake mixture into the center of the chocolate cake.
Bake for 20-25 minutes or until done. Immediately remove the mini Black Bottoms from the pan and cool on a wire rack. Repeat with remaining batter until all Black Bottoms are baked.
Store in an airtight container at room temperature or for longer storage, in the refrigerator.