Marilyn's Famous Rhubarb Crunch

6 c ups fresh rhubarb, cut into 1 inch pieces

¾ cup sugar

1 box (18 oz) yellow cake mix

1 cup coconut

1 cup chopped walnuts

½ cup butter, melted

butter spray

Preheat oven to 325. Butter a 9 x 13 baking pan. Arrange rhubarb in bottom of pan. Sprinkle with sugar and dry cake mix. Stir to mix. Sprinkle with coconut and walnuts. Pour butter evenly over the top. Spray top with butter spray until the dry cake mix is moistened. Bake for 45-55 minute or until light brown on top and bubbly on bottom.