Preheat your oven to 350°F (175°C).
In a mixing bowl, combine the softened cream cheese, sour cream, and powdered sugar until smooth.
Zest and juice the lemon, then add to the cream cheese mixture.
Prepare a baking dish by greasing it lightly.
Spread the lemon cake mix evenly in the baking dish.
Pour the cream cheese mixture over the cake mix.
Drizzle the melted butter over the top, ensuring even coverage.
Add blueberries on top, if using.
Bake in the preheated oven for 40-45 minutes, until golden brown.
Allow to cool slightly before serving. Top with whipped cream and lemon slices.