This is a congruent conflation of “off the top of my head” and “off the cuff”, both expressions meaning to speak without much thought or preparation. It is similar to the 9/16/12 post “he said it off the top of his cuff”. This malaphor came all the way from South Africa. An African National Congress (ANC) spokesperson during a radio interview, in avoiding difficult questions, responded with the opener: “Well, off the cuff of my head . . .” A shout out to Allan Muir for sending this one in!