This is taken from Allrecipes, with changes and comments from the comments on that website. First, the link to the original recipe. Now the better recipe:
12 fresh peaches, pitted and sliced or 2-32 oz. cans sliced peaches
1 cup water }
1 cup white sugar } or 1 c. peach juice from cans
1/2 teaspoon ground cinnamon
1 (18.25 ounce) package white/yellow cake mix
1 (8 ounce) package cream cheese
1/2 cup butter, melted
Preheat oven to 350 degrees F (175 degrees C).
Spread peach slices evenly into a 9x13 inch baking dish. If using canned peach juice, pour 1 cup of it over peach slices. If using fresh peaches, combine water and sugar in a small bowl. Stir to dissolve, then pour mixture over peaches. Sprinkle cinnamon over peach slices.
Cream together the cream cheese and cake mix. Spread mixture over peaches then drizzle on the butter or margarine. Another option is to cream the unmelted butter in with the cream cheese and cake mix.
Bake in preheated oven for 45 minutes, until golden.
*Skip the extra sugar if your peaches are already sweet (most fresh ones are if they're ripe and ALL canned peaches are sweet enough). If you're using another fruit, like blackberries or raspberries, then you'd need the extra sugar. Remember, the cake mix has sugar, too.
*Cream the cheese and cake mix together with a pastry cutter or a couple forks until it resembles a crumbly granola-type consistency.
*Melt the butter and pour it over with the liquid (use less liquid if your fruit is really juicy!) Alternately, cream the butter in with the cheese and cake mix (see above).
*Cinnamon is not always appropriate if you are using this with a different fruit. Other options that might sound better to you are nutmeg, vanilla bean specks or vanilla-flavored sugar.
*For a crunchy bonus, sprinkle the top with sliced almonds before baking.