The Cake Crew at Bala's Enterprise Park is installing a £250,000 production line to increase capacity to 750,000 cakes a week.
October is expected to be the busiest month on record, the company said.
A spokesperson said: "We would like to thank the Bala workforce for its performance in gaining this additional business through consistent quality."
The bakery supplies the major supermarket chains.
A Gwynedd bakery is creating 30 new jobs to meet demand for its cup and loaf cakes.