Idk about all of my ocs but: (going off the accents i think each have)

Coffee Cake - Germany
Mocha Gelato - South Korea
Salmon - Scotland
Nea Crepe, Vanilla Cappucino, and Latte Macchiato - various parts of England probably(latte macchiato and vani cappuccino are second gen South Korean immigrants)
Lionfish - either Ireland or England
Cinnilla Creme - France
Nightshade - Spain i think
Dorayaki and Blueberry Cakehound - the US i guess?

and that's all i can think of right now. the last handful of ocs i just haven't thought too deeply about ethnicity/nationality for them yet