Preheat your oven to 350°F (175°C).
Grease the bottom and sides of an 8-by-8-inch casserole dish with the melted butter.
In a large mixing bowl, combine cornbread mix, creamed corn, corn kernels, eggs, sour cream, mascarpone, and scallions. Mix until well combined.
Pour the mixture into the prepared casserole dish.
Bake in the preheated oven for about 45-50 minutes, or until the top is golden brown and a toothpick inserted in the center comes out clean.
Let it cool slightly before serving.