I remember when and a few other things were added to The Bake Stop and being more than a bit grossed out that they were there. Now that Half Baked has been a thing for a while, why not sell them there now?
The hot dog cake isn't as bad as the poop items in Quick Bites and the Poop Taffy in the Candy Shack. :D
It doesn't say the hot dogs are rotting or made of humanoid body parts. Maybe some of the anthropomorphic species eat it or even members of native Subetan races. It's even possible that some humans besides Carl and Pete like it.
A small number of Unliving moved to Atebus so it's possible there are some Unliving in Centropolis now. They'd like poop items and some of the other ghastly food items for sale in the main food shops. Why they were in the food shops years before the Unliving appeared only the staff knows. :D