Commander Foxworthy's "sweet Newton" declaration may have made her sound better educated than she actually is. During Ellen's schooling, mentions of "Newton" had nothing to do with the inimitably polymathic Sir Isaac, and everything to do with the miraculous work of James Henry Mitchell and Charles M. Rosen.
In 1891 Mitchell invented a double-funneled pump extrusion system allowing a continuous tube of dough to be pumped out pre-filled with a similarly-continuous cylinder of something else. That same year, Rosen used the machine to create tubes filled with fig jam, which he then cut and baked into cookies. The company to whom Rosen sold the recipe named those cookies after a nearby town—a town which has never been notable for its production of figs, cookie dough, or double-funnel pumped extrusion systems, let alone 17th-century polymaths.
So, yes, Captain. She WAS talking about the fig cookie, but she was using it as an epithet. How the 1200-year-old, double-funnel-extruded, fig-jam treat ended up as an exclamation of despair is a different story altogether.