The Cornish Language Board said 77 people sat the exam this year - a rise of 15% on the previous year.
Exams secretary Tony Hak said the spike is partly down to Saunders, whose Cornish language concept album has seen her play live on 6Music.
More than 1,200 people have taken the exams since they began in 1992.
The language is designated "critically endangered" by the United Nations group Unesco and is recognised as a minority language by the Council of Europe.
"Gwenno's album is a fantastic boost for the language," said Mr Hak.
"So people are seeing it a lot more around them and they have become interested.
"It's also because Cornish people are becoming more aware of their identity and sense of place.
"There's a growing awareness of the language from businesses who want Cornish branding."
Gwenno, who recorded her second album Le Kov (A sense of place) in Cornish, said it was exciting that use of the language was becoming more "casual".
"It's quite incredible that the language is alive. That shows its resilience because there hasn't been really any support."
The Welsh Music Prize winner said her native tongue was the perfect way to tell stories about the region.
"It has this huge rich history that not many people are aware of," she says.
"But [the language] offers another perspective and another narrative on Cornwall.
"It's something the wider population in Cornwall feel an ownership over.
"People are saying, 'let's just use it in the way its interesting or us or makes sense to us.'"
Exams secretary Tony Hak said the spike is partly down to Saunders, whose Cornish language concept album has seen her play live on 6Music.
More than 1,200 people have taken the exams since they began in 1992.
The language is designated "critically endangered" by the United Nations group Unesco and is recognised as a minority language by the Council of Europe.
"Gwenno's album is a fantastic boost for the language," said Mr Hak.
"So people are seeing it a lot more around them and they have become interested.
"It's also because Cornish people are becoming more aware of their identity and sense of place.
"There's a growing awareness of the language from businesses who want Cornish branding."
Gwenno, who recorded her second album Le Kov (A sense of place) in Cornish, said it was exciting that use of the language was becoming more "casual".
"It's quite incredible that the language is alive. That shows its resilience because there hasn't been really any support."
The Welsh Music Prize winner said her native tongue was the perfect way to tell stories about the region.
"It has this huge rich history that not many people are aware of," she says.
"But [the language] offers another perspective and another narrative on Cornwall.
"It's something the wider population in Cornwall feel an ownership over.
"People are saying, 'let's just use it in the way its interesting or us or makes sense to us.'"
