I did something similar myself yesterday by eating a large bread bun. Despite it being wholemeal and seeded, it raised my BS to a very unacceptable level that lasted above 3 hours. I didn't feel guilty because I did it on purpose as an experiment and was carefully monitored by my Libre sensor, but I learnt from doing it that despite excellent normal levels I cannot cope with ordinary bread and probably never will be able to.
Glad you enjoyed your treat, but please do be careful it doesn't become a habit.