I never thought I'd hear Tegan and Sara in an Oreo commercial, but I also never thought Tegan and Sara would make bouncy dance pop, so everything's up in the air at this point.
The Canadian duo provided a pretty awesome version of the "Wonderfilled" jingle for this "Dare to Wonder" ad from The Martin Agency (it first aired during the Grammys) promoting a series of limited-release Oreo flavors including berry, peanut butter, lemon and mint. Honestly, all those sound really gross, but the jingle is right in line with Tegan and Sara's lyrical sensibilities, and of course they didn't even write them—the ad agency did.
Living in a world where Tegan and Sara play a song they didn't write for the purpose of selling junk food feels a bit strange, but they've said they don't make albums to keep their old fans, so perhaps that same principle has been applied here.