FEINSTEIN’S/54 BELOW, Broadway’s Supper Club, presents Bonnie Milligan in Hallmarc’s A Christmas Murder on December 20th at 11:30 PM. Don’t speak! It’s Christmas in Charity Fails, a midwestern suburb where the third best baker, Sarah Jessica, is trying to win the Merry Christmas America cupcake pageant. But everything is thrown into chaos when the neighboring…