brownie vs cooky

brownie and cooky both are nouns.

Word	Noun	Adjective	Verb	Adverb
brownie	Yes	No	No	No
cooky	Yes	No	No	No

As nouns, cooky is a hypernym of brownie; that is, cooky is a word with a broader meaning than brownie:

Other hypernyms of brownie include biscuit, cookie.

brownie (noun)	cooky (noun)
square or bar of very rich chocolate cake usually with nuts	any of various small flat sweet cakes
(folklore) fairies that are somewhat mischievous	the cook on a ranch or at a camp