I really like marshmallows. Thankfully, marshmallows are dairy-free but eating them straight out of the bag doesn't seem like the most honorable way of consuming them. Since I shun margarine also, rice crispy bars have been on my list of things I can't eat for awhile- but no more! I could always eat the peanut butter ones- but- there's no marshmallows in that recipe...
Because I'm that kind of a baker, I'm going to give you an annoying outline of the recipe instead of an actual recipe. I like to know how things work, rather than just follow directions one time. As a general rule in non-dairy baking, to substitute oil for butter, one uses half the amount (for example 1/2 cup butter= 1/4 cup oil). This works in cookies and cakes and breads of all kinds- substituting oil for butter or shortening even works with pie crust (trust me, my Mom and I could LIVE off of pie). Taking all that into account this is how I made my rice crispy bars:
First of all, I halfed the recipe (I didn't want to end up with a giant pan of rice crispy rocks) (plus I knew no one else would eat it). I used 3 cups of rice crispys and two cups of marshmallows. I'm really horrible at melting marshmallows on the stove- but I melted them with 2-3 tablespoons of canola oil. You might need more or less- my marshmallows were sticking really bad to the pan so I added more oil. The rest is like the normal recipe- without buttering the pan of course. My Mom said they needed butter flavor (yes, you can buy artificial butter flavor... ) but I really liked the marshmallowy taste. They were chewier than normal- meaning it took a little more effort to bite off a chunk and mash it down- however, this is why I give an outline so that you can experiment and figure out how to make yours the way you like them! Be not afraid!