Inactive Tutor answered 04/29/19
Tutor
New to Wyzant
You're right when saying 싱겁다 tends to have a negative connotation.
Based on how you explained it, I think the best way to phrase this is: "이 빵은 너무 느끼하지 않아서 좋아요."/"이 빵은 버터 맛이 많이 안 나서 좋아요."
Good look with your Korean studies!