Preheat the oven to 350°F (175°C). In a mixing bowl, combine sliced peaches, sugar, and lemon juice. Stir until well mixed.

Pour the peach mixture into the bottom of a greased 9x13 inch baking dish.

Sprinkle the dry cake mix evenly over the peaches.

Drizzle the melted butter over the cake mix, ensuring even coverage. Sprinkle nuts on top if using.

Bake in the preheated oven for 45 minutes, or until the top is golden brown and the peaches are bubbly.

Let cool for a few minutes before serving. Enjoy warm or at room temperature.