In a large mixing bowl, pour in the sliced peaches along with their syrup.
Add the granulated sugar and ground cinnamon to the bowl. Stir well to combine.
Transfer the peach mixture into a greased 9x13 inch baking dish, spreading it evenly across the bottom.
Evenly sprinkle the dry yellow cake mix over the peach layer, ensuring it covers all the peaches.
Slowly drizzle the melted butter over the dry cake mix, making sure to cover as much of the mix as possible. Do not stir; leave it as is for a more unique texture.
If desired, sprinkle chopped pecans over the top for added crunch and flavor.
Bake in the preheated oven for 35-40 minutes, or until the top is golden brown and the peaches are bubbling.
Remove from the oven and let cool slightly before serving.
Notes
Serve warm, optionally with a scoop of vanilla ice cream on top for a delightful contrast of temperatures.