Preheat the oven to 350°F (175°C) and grease a 9×13-inch baking dish.
Pour the lemon cake mix into the prepared baking dish, spreading it evenly.
Spoon the lemon pie filling over the cake mix, ensuring even distribution.
In a mixing bowl, beat the softened cream cheese until smooth. Drop spoonfuls of cream cheese over the lemon pie filling layer.
Drizzle the melted butter over the top of the cake evenly.
Bake in the preheated oven for 40-45 minutes or until the edges are golden and a toothpick inserted in the center comes out clean.
Allow the cake to cool slightly before serving. Cut into squares and serve with a dusting of powdered sugar or a dollop of whipped cream if desired.