With Eartha Kitt meowing her way through a fresh batch of catnip at The Carlyle, Tammy Grimes and the legendary Marilyn Maye back at the Metropolitan Room, and jazz icon Mark Murphy at the Iridium, the fall cabaret scene is off to a rousing start. For maximum joy, focus on KT (no periods, period) Sullivan at the august Algonquin’s Oak Room (through Oct. 13). Larky and luscious as ever, she’s also singing better. This is her 10th engagement here, and one of her rare solos. This is as it should be. She doesn’t’ need a musical partner. In fact, she’s more confident and polished on her own, and her repertoire has fewer limitations. O.K., they give her act a title that looks good on a poster, but “Autumn in New York” is nothing more than excuse to unveil a whole new batch of exquisite and often overlooked songs from Broadway musicals. If you want to get technical, they all started life when the New York theater did—in the autumn of the year. But I don’t care if they opened on Easter Sunday. They’re all worth hearing again, as long as KT Sullivan sings them. Insouciant, effervescent and bubbly as Veuve Clicquot, KT sashays her way through “I’m Just a Little Girl From Little Rock” channeling Carol Channing and Marilyn Monroe. When she did Noël Coward’s “World Weary,” all I could think of was a tongue-in-cheek Mae West. On a gorgeous arrangement of “And I was Beautiful,” an obscure treasure Jerry Herman wrote for Angela Lansbury in Dear World, she lights the night with her special brand of internal neon. Taking the ultimate showbiz survivor’s anthem, Irving Berlin’s “There’s No Business Like Show Business,” at a slower pace than usual, she gets to the subtext of a song that defines an entire way of life. And in between, she crowds the playbill with one surprise after another, unlocking the keyholes of Sondheim, Brecht, Porter, Rogers and Hart, Jule Styne, Kurt Weill, Lerner and Lowe, Vernon Duke, and more—up to and including new emeralds from scores as fresh in the memory as The Light in the Piazza and Grey Gardens. Accompanied by the first-rate Tedd Firth on piano and bassist Steve Doyle, her arrangements are as unexpected and delightful as her witty repartee. She still bares the historic poitrine of Lillian Russell, but KT sounds dreamier than before, her lust for life and sense of humor are keener, and she’s learned a lot about phrasing. This is a girl with uncompromising taste, so if you’re looking for something from Avenue Q, Legally Blonde, or Andrew Fucking Lloyd Webber, keep moving. For everyone else: run don’t walk to spend some valuable time with a delectable doll from Oklahoma who seems as much a part of Manhattan after dark as an opening night Broadway marquee. Watching KT Sullivan reminded me of that great line Burt Lancaster aimed at the smarmy Tony Curtis in Sweet Smell of Success: “I’d hate to take a bite out of you—you’re a cookie full of arsenic.” KT Sullivan is just the opposite. She’s still a cookie, cookie—but delicious enough to eat.