I see vegan marshmallows advertised on-line, fwiw.
I was not recommending rice krispie tests, but just using a similar procedure with some other sticky sweet buffer to make fruit&nut bars.
Its pretty easy to find vegan marshmallows at a natural foods store, you’d also need vegan margerine. I suggest NOT CAKE. I once did a vegan gluten free cake for a wedding (my brother in laws wife was vegan and did not eat gluten) and it tasted like sawdust - although she thought it was great (she hadn’t had cake in years).
In fact, if you go to a natural foods store (coop, whole foods) you may find all sorts of allergen free boxed products. They aren’t CHEAP. I have a boxed GF poundcake from 123 Gluten Free that is really good - it takes eggs and margerine, but they have a vegan version receipe using ground flaxseed inside the box (note, I’ve never made it that way, and honestly, wouldn’t myself).
Cookies in general are pretty tough. As someone gluten light, I have staples, but they are all heavily egg based (a balsamic vinegar chocolate meringue. Italian almond paste cookies that are SO GOOD) and not cheap. At the point in time you start making cookies for a group and cater to someone with that extensive of a dietary restriction, you are basically screwing the rest of the group out of a good cookie.
These are more kids’ recipes but might suit you:
Chocolate crackles
Cornflake kisses (apparently. a.k.a. honey crackles). You would have to use a vegan butter for that one.
Actually a classic Christmas recipe which is gluten free and easily made vegan is White Christmas, made with copha (solidified coconut oil), rice crispies and glaced fruit - it’s an absolute tradition here in Australia. The recipe I use contains milk powder, but this vegan site omits it and I reckon it would be fine without.
you can also use some marshmallow cremes which works for the ingredient in a recipe and are vegan.
For vegan, I always go straight to the Veganomicon. I’ve never even come close to vegetarianism, but still keep a copy of that book lying around to accommodate certain friends.
Margarine isn’t vegan? Huh, whaddya know? It doesn’t sound like finding vegan margarine would be too hard, though - it sounds like some of the common brands are vegan.
Oh yeah: Mori-nu has a number of recipes on their site for things using silken tofu; we made their tofu pumpkin pie for Thanksgiving for years (my son was largely dairy free for a while). Put that in a gluten free crust of some sort.
And Cat Whisperer: true - shockingly; most have casein which is derived from milk. Bizarre. We used to buy a cream cheese substitute made from soy. All but one brand had casein in it which is amazing. If you could have milk, you’d have the real stuff. Vegetarian “cheese” almost always has casein, you have to look very carefully. There is a brand of margarine that our grocery store carries (EarthBalance, I think) that’s safe.