Preheat the oven to 400℉. Spray a 9x13-inch baking dish with nonstick spray and set aside.
Place the cream cheese, sour cream, salt, pepper, paprika, and garlic powder into a mixing bowl. Using an electric mixer, mix to combine.
Add the shredded cheddar cheese and corn into the cream cheese mixture and fold together so that everything is combined evenly. Set aside.
In a separate bowl, combine the cornbread mix, egg, and milk. Then, transfer the corn mixture into the baking dish.
Spread the cornbread mix evenly over the top. It will not cover completely edge to edge, just spread as evenly as possible on top of the corn.
Bake for 45 minutes or until the top is golden brown and cooked through.
Let the casserole rest for 10 minutes before serving.