Maybe that's a little bit misleading, given that "gustar" is a verb, while "нужны" here appears to be an adjective (?)
With that in mind, a somewhat more fitting (if a bit clumsy-sounding) analogue could be "La manzana es necesaria (para mi)." vs. "Las manzanas son necesarias (para mi)."
No, because нужны is used here as a short adjective in the predicate (milk & bread are necessary to me). This is probably the most common form when expressing "I need...", etc.
You can see the long form occasionally when it's right before the adjective and not in the predicate (ie not after "to be" in English translation), for example, Вся нужная информация у меня в голове. = All the necessary information is in my head.