Heat oven to 350°F. Lightly grease a 9×13-inch baking dish.
Melt the butter until just liquid, then let it cool 2 minutes.
Whisk sour cream with the melted butter in a large bowl until smooth.
Stir in the creamed corn and the drained corn kernels.
Fold in cornbread mix, salt, pepper, and paprika until just combined.
Stir in about 1 cup cheddar and the green onions, reserving the rest for topping.
Spread the batter in the dish and sprinkle with remaining cheddar.
Bake 40–45 minutes until set in the center and golden. Rest 10 minutes before serving.