1. Preheat oven to 350°F for glass or metal pans, 325°F for dark or non-stick pans. Grease bottom of pan with shortening or cooking spray.
2. Combine brownie mix, eggs, pureed avocado and water in large bowl. Stir until well blended (about 50 strokes). Spread in greased pan and bake immediately.
3. Bake for amount of time per instructions on box. Brownies are done when toothpick inserted 1 inch from edge of pan comes out clean. Cool completely in pan before cutting and serving.