Preheat the oven to 350°F (175°C). In a mixing bowl, combine sliced peaches, sugar, and lemon juice. Mix well and pour into the bottom of a greased 9x13 inch baking dish.

Sprinkle the dry yellow cake mix evenly over the peach mixture.

Drizzle melted butter over the cake mix. If using, sprinkle chopped pecans on top.

Bake in the preheated oven for 40 minutes or until the top is golden brown and the filling is bubbly.

Remove from the oven and let cool for a few minutes before serving.