According to The Encyclopedia of Cajun Culture the correct French spelling of the familiar phrase is "Laissez les bons temps rouler!" ("Let the good times roll!"), but there have been song titles spelled "Bon Ton Roula" (aka "Bon Ton Roule") by Clarence Garlow, 1949, and "Bon Ton Rouley" by Lawrence Walker, ca. 1958. So far I have not been able to find lyrics to either of them, but maybe someone else will take up the search.