Preheat oven to 350 degrees F. Spray a 9" x 9" baking dish or 13" x 9" baking dish (see recipe note) with non-stick cooking spray.
Combine brownie mix, oil, water, and eggs in a large mixing bowl. Stir well with a spoon until thoroughly combined. Pour brownie batter into prepared baking dish and spread out into an even layer.
Sprinkle batter with half of the chocolate chips and scatter the Wavy Lay's over the top, breaking up any larger chips to fit. Sprinkle with remaining chocolate chips.
Bake according to package directions; approximately 30 to 35 minutes for a 9" x 9" pan or 28 to 31 minutes for a 13" x 9" pan.
Allow to cool completely before cutting and serving.
I used a 8" x 11" rectangular baking dish to bake the brownies pictured in this post. This is equivalent to a 9" x 9" baking dish and will produce a thicker brownie (as pictured). For a lower profile brownie you can use a 13" x 9" baking dish. Adjust baking times accordingly.