Green’s Dictionary of Slang

(orig. US) an excl. of enthusiasm and approval; esp. in phr. with a hey nonny-nonny and a hotcha-cha.

1928		R. Fisher Walls Of Jericho 190: Hot you, baby —!
1933		S. Walker Night Club Era 250: ‘[Florence Mills] has the genius of the grotesque . . . Her body speaks.’ Hot-cha.
1937		Jimmie Lunceford & His Orchestra ‘Teasin’ Tessie Brown’ 🎵 Watch her! Soon you say she’s gotcha, / Hotcha! Like a shot of scotch-a, / Watch her! my, but she is hotcha!
c.1940		‘Tillie & Mac with Mr Simpkins and Bubbles’ [comic strip] in B. Adelman Tijuana Bibles (1997) 24: Bubbles you’re sure a sweet lay. Hot cha!
1952		(con. 1937) G. Fowler Schnozzola 203: The dancer put his hands to his own throat, then said, ‘Hot-cha! Hot-cha!’.
2001		S. King Dreamcatcher 274: Somebody up there likes me! Hotcha!