Sour Cream Bran Muffins

Recipe from Gourmet, October 1991 Notes: This issue of the magazine features the best-loved baked goods from the past decades. 1981 was the initial publication of this muffin recipe and it's still a delight. Of course, with ½ cup of butter and 1 cup of sour cream, it's bound to be delicious and rich. The molasses gave them a nice colour and I also added chopped walnuts to the batter for crunch. Like the other reviewers commented on Epicurious, these were very light and moist, quite unlike most bran muffins.
Update: I made a batch replacing most of the sour cream with yogurt, and the raisins with one peeled, chopped apple. They turned out great.