From baby +‎ cakes.

• (General American) IPA^(key): /ˈbeɪ.bi.keɪks/

• Audio (General Australian):

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babycakes (uncountable)

1. (US, slang) A term of endearment for a young woman.
   • 1979 July 2, Billie Jean King, quotee, “Reflection on the Seedings Fills Pause at Wimbledon”, in The New York Times‎^[1]:

     Mrs. King is delighted that there are so many Tracy Austins in professional tennis these days. She refers to them as “babycakes,” and not patronizingly.

• “babycakes n.”, in Green’s Dictionary of Slang, Jonathon Green, 2016–present