Grease a 9×13 pan with non-stick spray. Cover the bottom with peaches. Sprinkle a little sugar over the peaches to soften and bring out their juices.
In a medium sized bowl, combine the cookie mix and margarine. Combine with a fork to make a crumble.
Spread crumble over peaches and bake at 350 degrees for 30-40 minutes; until the crumble is golden brown and peaches are soft.
Serve warm with ice cream!