Is it the garlic/butter you've been craving, or the bread? I know the combination is the perfect match, but I wonder if your body is craving a certain part of it.
Let's see...if we go by the old adage that our bodies know what they need:
craving bread = body wanting carbs, calories or yeast.
(If you are not on Atkins, or other diet, and your um, female areas are all in normal condition...this is probably not it.)
craving butter = body wanting salt
(Salt cravings can be a symptom of diabetes, high blood pressure and sickle cell anemia.)
craving garlic = body wanting potassium