Toast or yogurt? Isn't it kind of obvious? Both, of course. Especially since this is a kind of a study of wether you like it or not. Also, what's stopping you from putting yogurt on the toast and then some jam? If it's not too thick you can dip a cracker in it. Ideally you would make some pancakes and put it on them. Or dip a rolled-up pancake in it.
I don't like pumpkin, but I'm curious what the walnut is doing for it. Do share your findings afterwards :)