Uh-Oh! Oreos (Nabisco)
The packaging says it all. Nabisco goofed and this is Oreo gone backwards. Instead of chocolate biscuits with vanilla creme filling, Uh-Oh! Oreos were vanilla biscuits with chocolate creme filling. According to that same packaging, Uh-Oh! Oreos were here to stay…not quite.
Uh-Oh! Oreos were eventually rebranded as Golden Oreos: vanilla biscuits with vanilla creme inside. Golden Oreos sold much better than Uh-Oh! Oreos and are still widely available today.