Green’s Dictionary of Slang

(US prison) confectionery sold to the prisoners.

1971		E.E. Landy Underground Dict. (1972) 196: wham whams and zoo zoos [...] Penny candies that are purchased in prison canteens.
1971–2		C. Shafer ‘Catheads [...] and Cho-Cho Sticks’ in Abernethy Bounty of Texas (1990) 217: whams, n. – cookies. [Ibid.] zoo-zoos or zuzus, n. – cookies or candies.
1972		E. Sanders Family 306: She gave linda Kasabian some Zu-Zus — Manson’s term for candy.
1981		Maledicta V:1+2 (Summer + Winter) 267: A phrase that must have been conceived by a person with a playful imagination is zoo-zoos and wham-whams for confections, usually small packaged cakes, pies, candy or gum obtained from a vending machine.
1990		S. Morgan Homeboy 152: When he made the canteen cart, the beaners ripped off his zuuzuus and whamwhams.
1992		Bentley & Corbett Prison Sl. 68: Wham Whams Store-bought snacks [...] Zoo Zoos Sweet snacks, cookies or potato chips [...].
2005		Prison Slang Mommyblogger mydogharriet.blogspot.com 23 Sept. 🌐 So your shortie jacked some wham whams from her ace-duces clavo? [Ibid.] You can even hook her up with some zoo-zoos if she has made amends to your satisfaction.