Here are the substitutions that I made:
For the Cupcakes:
- I replaced the butter with vegan margarine at room temp. I used the brand Smart Balance Light with Flax (be careful, this product is vegan, but the brand is not entirely vegan)
- I used EnerG Egg replacer to substitute for 2 eggs
- Obviously I used vegan sugars
- I used Silk Soy milk with Omega 3s in substitution for whole milk
- I used vegan chocolate chips, don't recall the brand
I found that I had to bake the cupcakes a bit longer than their recipe suggested, but that may have something to do with the altitude here...or something. I am pretending I know why it happened that way when I am no baker.
For the Frosting:
- I replaced the butter and milk the with the same vegan brands listed above
- I found that the frosting wasn't quite to my liking so I added about 1/3 of a cup (1 Tbs. at a time) of confectioner's sugar, until I had the flavor I was interested in.
I didn't pipe on the frosting, because I had enough dirty dishes at that point, I just spooned it on. The results were really delicious! If you are a fan of the peanut butter and chocolate combo then I recommend that you give this a try!