The phrase "mini ones" refers to small versions of something. It is used to describe things that are smaller in size but similar in nature to larger ones.
Sentences with «mini ones»
I always make mini ones and cover them with peanut butter or sliced strawberries. (theskinnyconfidential.com)
I only made an extra mini one in a jar so you could see the layers. (treatswithatwist.com)
I want to share with work buddies, so I figured making mini ones would be easier. (wishesndishes.com)