Let's see...
Canada: The only places I can even think of for QS anything here is McD's right before the pavilion and an espresso/coffee kiosk right after it. Nothing really Canadian. Perhaps someone can help me out here?
UK: I don't think there's any fresh baked pastries here, but you could grab shortbread cookies from the QS (Yorkshire County Fish Stop.)
France: This has been pretty well covered. Def. one of the best places! Since you'll be eating probably a lot of heavy stuff, can I recommend the strawberry tart? Delicious! (They also have a Crepe stand in France...I'd avoid. They're okay. Really not authentic, leave something to be desired.)
Morocco: Baklava in the Tangerine Cafe, easy peasy!
Japan: Yakitori House (the QS here) has the Ginger Cake. Probably the best bet here. Or I'd go inside and get some sweets.
America: Funnel Cake! Duh...what else
Italy: Already been mentioned. I don't know the snacks here off hand
Germany: This is a hard one...I mean, do you go with the strudel? Or the pretzel?

(Strudel can be bought at the QS location.)
China: I'd veer a little off here and get the Ginger Ice Cream. Seems appropriate.
Norway: I think this one is obvious:
Need I say more??
Mexico: (phew...last stop...) They have churros...but haven't heard good things about the Disney Churros. Also listed on the QS menu, Bunuelos. I have no idea what those are though.