Creating your Tangy Lemon Cream Cheese Dump Cake with a Buttery Crust is an easy and straightforward process. Follow these steps to ensure a delicious outcome:

1. Preheat the Oven: Begin by preheating your oven to 350°F (175°C).
2. Prepare the Dish: Grease a 9×13-inch baking pan with cooking spray or butter.
3. Mix the Cream Cheese Filling: In a medium bowl, combine the softened cream cheese, powdered sugar, lemon juice, sour cream, and lemon zest. Mix until smooth and well incorporated.
4. Prepare the Cake Batter: In a large bowl, combine the lemon cake mix, melted butter, and eggs. Stir until just combined. This mixture will be thick.
5. Layer the Cake: Pour half of the cake batter into the prepared pan, spreading it evenly across the bottom. Next, pour the cream cheese filling over the batter, spreading it gently. Finally, pour the remaining cake batter on top, without mixing.
6. Add Soda Topper: Drizzle the lemon-lime soda or sparkling water over the top layer of batter. This will help create a light, fluffy texture as it bakes.
7. Bake: Place the pan in the preheated oven and bake for 45-55 minutes, or until the top is golden brown and a toothpick inserted in the center comes out clean.

Once baked, allow the cake to cool for a few minutes before serving.