Preheat oven to 350°F. Grease a 9×13 inch baking pan with cooking spray.
In a large bowl, stir together brown sugar, vegetable oil, vanilla extract, coffee, eggs, baking soda, salt, flour and ¾ cup chocolate chips. Pour into baking pan. Sprinkle remaining chocolate chips on top.
Bake for 45 minutes or until a toothpick comes out of the centre clean. Let cool before frosting and cutting into squares.