2 3oz bars of vegan chocolate. I used Endangered Species, one cacao nibs and one coffee beans. The bat and the tiger, I can't remember which was which.
Mix peanut butter, yeast and sugar. Spread them on a plate about a 1/2 inch thick and put in the freezer to let it get a little hard. You will cut it in pieces later to put in the center of the cup.
Melt the chocolate. I used an old enamel pot and submerge it halfway in warm water. The chocolate melts slowly but it doesn't scorch that way.
Pour chocolate into glass custard cups, enough to cover the bottom
Take your hardened peanut butter mixture and cut off a piece the size you want. I went with about a 50c piece.
Place it on the chocolate in the cup.
Pour the rest of the chocolate on top
Pop it in the fridge for an hour or more so it sets up.
When you are ready to eat them, fill a pan with 1" of warm water and put the cup in the water. Leave it for a minute or two and the peanut butter cup should pop right out with the help of a bread knife.