In a 9x13 inch baking dish, pour the undrained peaches evenly across the bottom.
Sprinkle the yellow cake mix evenly over the peaches, ensuring full coverage.
In a small bowl, mix the cinnamon into the melted butter, then drizzle this mixture over the cake mix layer, making sure it covers as much of the mix as possible.
If you're using chopped pecans, sprinkle them over the top of the cake mix.
Bake in the preheated oven for 45-50 minutes until the top is golden brown and the edges start bubbling.
Once done, remove from the oven and allow to cool for a few minutes before serving.
Notes
Serve warm with vanilla ice cream and drizzle warm peach syrup over the ice cream.