Melt butter in 13x9 cake pan -- Sprinkle brown sugar evenly on top.
Drain peaches, reserving peach syrup.
Add enough water to make 1 1/3 cups liquid -- set aside.
Scatter raspberries on top of peaches.
In a large mixing bowl, combine peach syrup mixture, cake mix, eggs and oil.
Beat on medium speed for 2 minutes.
Pour batter evenly over fruit.
Bake for 45-50 minutes or until a tester comes out clean.
Let cool in pan on a wire rack for 5 minutes, then turn upside down onto a large platter or cookie sheet.
Serve warm with a generous dollop of whipped cream or cool whip, if desired.
****Note.canned peaches work best for this recipe becuse they keep their color and texture during baking.If you want evenly sized slices.buy peach halves and slice them yourself.I have also used 1/2 cup maraschino cherries in place of raspberries.