There were surprisingly very few things we found on our short trip to Canada that seemed uniquely Canadian. Sure, they have some different products than the US but a lot of them seemed to stem from their British ties instead of being authentically Canada-based.
Maple-Everywhere you went, you could find maple-flavored things. Donuts, fudge, drinks, cookies.
Raisin Pie/butter pie-This was mentioned on a website as being a Canadian food, but the ones I found were horrendous snack-cake packaged gloopy corn-syrup mini-pies. I passed on them.
Smarties-These are UK, not Canadian but I DID enjoy them!
Casinos-Wow, it was most likely the area we were in but there seem to be casinos and signs for casinos all over!
Real Canadian Superstore-I was hoping this would be a good place to find some unique items but it was really disappointing. It kind of made it clear that Canada is pretty much just a more northern USA as far as groceries go. Macaroni and Cheese IS called Kraft Dinner, though.
Tim Hortons-Just as Dunkin Donuts were thick in the East, Tim Hortons were just about everywhere in Canada. And their donuts were WAY better!