Box brownies are good, but why not kick-it up a notch and make them GREAT! The family will love to help make these goodies.
Pre-heat oven to 350°F. Mix together the DRY brownie mix, egg and water. Add apple sauce (see amounts in note below for your box mix). The batter will be slightly lumpy, do not overmix.
Spread evenly in greased 9x13-inch baking pan. Bake according to box directions.
Sprinkle marshmallows, nuts and chocolate chips on the top. Bake for an additional 3-5 minutes until marshmallows are just starting to brown. Cool completely and cut into bars.