The fire was reported shortly after 6 p.m. Thursday at the Serpe's Bakery located at 1411 Kirkwood Highway.
Officials said Elsmere Fire Company firefighters encountered flames shooting through the roof.
State fire investigators were called to the scene and are currently searching for the fire's origin and cause.
Officials said two firefighters were transported to Christiana Hospital for treatment of heat exhaustion. They're expected to be OK.
The amount of fire damage is not known at this time.