1 (16 ounce) can peaches in light syrup
1 box yellow cake mix
1 stick (1/2 cup) butter, cut into thin slices
Pour peaches and syrup into 9 x 13-inch cake pan. Sprinkle cake mix over peaches. Top with butter slices. Bake at 350 degrees F until golden brown.
Serve with Cool Whip if desired.