Baked Corn Casserole

1 (8 1/2 ounce) package corn muffin mix
1 (15 3/4 ounce) can whole-kernel corn, drained
1 (14 3/4 ounce) can cream-style corn
1 cup sour cream
1/4 cup (1/2 stick) butter, softened
1 egg

Heat the oven to 350 degrees F. Butter a 2-quart casserole dish or spray with nonstick cooking spray.

In a large bowl, combine all the ingredients. Mix well. Pour into the casserole dish. Cover and bake for 30 minutes. Uncover and bake for 30 to 35 more minutes, or until set and the top is golden.

Serves 4 to 6