I love Seasons in the Land for lots of food items - but all the cakes, pastries, etc (including a red velvet Mickey whoopie pie!) are great and on the DP (if I remember correctly).
At MK, my favorite snack is the Dole Whip Float (Aloha Isles).
At Epcot, my favorite snacks are the Caramel Corn (Germany, Karamel Kuche - you can only get the small bag with the DDP credit), Cloudberry Horn (Norway, Kringla), and Cafe au Lait Mousse (France, Les Halles).