The actress, 26, wears Daisy Dukes and an unbuttoned chambray top in a sexy ad for the fast food chain's new Midnight Moonshine Burger.
"Frankly, I like to eat a burger," Panettiere tells PEOPLE. "I'm Italian, so I'm not very good at curbing myself. I think that we should allow ourselves that. I think [otherwise] then we'll all end up hangry, and nobody wants to be hangry!"