Lawrencium
Google
A walk-up window bakery with a small but excellent selection of whole grain breads, muffins, and cookies, as well as dried fruits, sugar-free yogurt, and a few flavors of nieve (we liked the pina colada). They have a few other minor items as well.
The people there were always very friendly and helpful and patient (even with a dumb tourist like me). I consider this a must-go-to place in San Blas. Their yogurt helped settle our “travellers’ belly.”
Be aware that the icon on Google maps makes it look like the service window is on the east side of the building but it is on the west (Batallion Street).