Preheat oven to 375 degrees.
Combine the first 5 ingredients. Beat for 2 minutes with an electric mixer - or beat really good by hand with a whisk. Stir in 2 cups of chocolate chips.
Spray a 9x13 baking dish with non-stick cooking spray. Spread the batter into the pan, and bake for 25 minutes or until a toothpick inserted in the center comes out clean.