Preheat oven to 350 degrees. In a 9x13" pan or oval baking dish, add the peaches to the bottom of the pan or dish. (If using frozen, make sure they're completely thawed. If using canned, drain off the juice.)
Top the cake mix crumble with the chopped pecans. Bake the cobbler for 40-45 minutes or until golden brown.
Let cobbler cool slightly for 10-15 minutes before serving. Serve warm, and top with vanilla ice cream, if desired.
Serve warm over vanilla ice cream. Refrigerate or freeze any leftovers.