Units responded to a citizen's report of smoke coming from Cafe des Croissants Grateful Bagels at the corner of Brockwood Avenue and Fourth Street at around 2:20 a.m., according to the Santa Rosa Fire Department.
Arriving firefighters reported finding substantial smoke and heat throughout the building, with flames in and around the coffee roaster that had spread into a portion of the attic.
Crews vented the roof with chainsaws and forced entry to the building, according to the fire department, and the fire was declared under control in about 10 minutes.
No one was injured fighting the fire.
Flames caused approximately $300,000 in damage to both the structure and the contents of the building, according to the fire department.
A preliminary investigation revealed that the fire was likely started by a malfunction in the coffee-roasting machine that caused the beans to catch fire and spread flames through the interior of the building.