I typically use Trader Joe's Pound Plus 72% cacao dark chocolate bars (the BIG ones!). Each bar is 17.6 ounces, so 4 squares is roughly 1.5 ounces of chocolate. This equates to roughly 1 full bar of Hershey's dark chocolate or ½-3/4 bar of Dove dark chocolate. I'd suggest starting with at least half a bar, and melting/mixing more dark chocolate as needed.
Either Oreo's or your favorite gluten-free alternative (TJs Joe-Joe's, I'm looking at you!) can be used in this recipe.
If you prefer to keep these milk chocolate, substitute the dark chocolate for blocks of milk chocolate or more Andes Mints.
Dip the leftover creme centers in chocolate as well! They will be just like spearmint-flavored peppermint patties.