Green’s Dictionary of Slang

(US) a frigid woman; thus her ‘frozen’ vagina.

1972		R.A. Wilson Playboy’s Book of Forbidden Words 99: Eskimo Pie. A frigid woman.
1977		Maledicta 1 (Summer) 17: If she is actually frigid [...] Only a frigid midget with a rigid digit can handle her Eskimo pie.