Mix all ingredients together except for the chocolate chips and pour into pan.
Sprinkle chocolate chips on top and put in oven. After 1 minute, take the pan out and with the tip of a kitchen knife or toothpick, swirl the chocolate chips around to give it a marble appearance. Put back in the oven and bake for 12-14 minutes.
Recipe Notes
For a 9 x 13 pan, double the recipe and bake twice as long.