Preheat the Oven: Preheat oven to 350°F. Lightly coat a 9 x 13-inch baking dish with cooking spray.
Layer the Filling: Spread 2 (21-ounce) cans lemon pie filling evenly in the bottom of the prepared dish.
Add Cake Mix & Cream Cheese: Sprinkle half of the 1 (15.25-ounce) box yellow cake mix evenly over the lemon filling. Distribute cubed 1 (8-ounce) block cream cheese evenly over the top. Sprinkle the remaining cake mix over the cream cheese in an even layer.
Add Butter: Pour 1 cup melted unsalted butter evenly over the top of the cake mix, making sure to cover as much of the surface as possible.
Shake: Give the pan a little shake to help any excess fall into open areas and prevent dry heaps from forming.
Bake: Bake for 50 to 55 minutes, or until the top is golden brown and bubbly.
Cool and Serve: Remove from the oven and let cool for 10 minutes before serving. Best served warm!
