Preheat oven to 350°F. Grease a 13×9-inch aluminum foil baking pan.
Read through this recipe entirely before you begin, as you will need to divide ingredients into separate batters in order to create two layers.

Microwave together the chocolate and butter on high setting 2 minutes. Stir in 2 cups of the sugar and blend well. Stir in 4 eggs and 1 cup of flour. Spread this mixture in the greased pan.

Beat cream cheese, gradually adding remaining ingredients. Combine well.

Spoon second mixture over batter already in pan. Swirl together lightly stirring with knife to create a marble-like pattern. Bake in Preheated 350 degree oven for 40 minutes or until toothpick has grainy fudge bits but is not clean, like in a cake. Be careful not to overbake.