Lakeside Mall. 25 minutes East (by train) from Tower Bridge (well, Fenchurch Station).
Lower Level outside the entrance to Marks & Spensers.
Place called "Made in Heaven".
Oreos. Bags and bags of them, and double stuffed too. Individual oreo packs. Hershey Syrups. Hershey Bars. Hot Tamales. York peppertmint patties. Apple Jacks. Lucky Charms. Oreo cereal. Marshmallow Fluff. Mike & Ikes. Hershey Kisses. Jelly Bellys. Fanta. Tab. Baby Ruths. Reese's Bars and Cups and Bites. Chips A Hoy Cookies. Jif. Crunchy Jif. Hersheys cookies & cream bars.
I nearly cried when I walked in there today. It's been around a few weeks but I've never gone in.... things are a bit pricey - £8 for a pack of Oreos - but still, there were several bags of them!
I stood there for quite a while and tried to memorize their stock so I could post it here - hope I did a good enough job.