"what to Expect in the First Year" has a recipe for carrot cake involving carrots, raisins, apple juice, wholemeal flour, veg oil and eggs - no sugar, no butter... Haven't made it for ages cos dd eats veg ok now.
But I do make pumpkin/squash savoury muffins and carrot pancakes cos they're nice.
Also chocolate courgette muffins - on the basis that if I'm giving her a cake anyway, she may as well have one with some veg snuck in. And you can't tell its in there (haven't told dh either).
Oven "chips" made out of sweet potatoes are nice (coat sliced potato in beaten egg white, bake at 220c for 30 min).
And you can bung pureed fruit/veg in anything - spag bog, lasagne, casserole, weetabix...
Dd has a bowl of peas as a snack, because I can't stand them so we never have them at meals, so she doesn't realise they're not sweets .
Annabel Karmel has loads of recipes for fried vegetable sausage type things. Far too much effort if they'll eat veg any other way but good if they won't!