TORONTO - Vancouver-born celebrity Jason Priestley will help Tim Hortons pick the winner of a contest it's launched asking Canadians to design a new doughnut.

The competition offers a $10,000 grand prize to the person who designs its next pastry, using a website and Facebook page dubbed "Duelling Donuts."

Priestley had a cameo in an episode of the sitcom "How I Met Your Mother" last February that played on the idea of a Canada obsessed with Tim Hortons.

The episode featured a faux documentary where Priestley bragged about his role in the creation of a new doughnut called "The Priestley." Tim Hortons later made the doughnut by stuffing a chocolate Timbit inside a strawberry-vanilla doughnut.

Tim Hortons says it hopes to find similarly original doughnut ideas, asking the public to try to beat "The Priestley."

Priestley and a panel of other judges will choose eight finalists from the entry pool, open until July 21, before the public votes on a winner in August.