I discovered these the other day and they are very simple to make.
This is my version
I used a silicon canape tray for the mould. You could use little muffin cases. Whatever you use, you want it small and easy to remove.
Put the silicon tray into freeze. Melt 200 grams of 85% dark chocolate. Take tray out of freezer and coat the bottom and sides of each mould with chocolate. Put tray back in freezer for a few minutes. You will now have a tray of chocolate cups. Take out and put a teaspoon of no added sugar peanut butter in each chocolate cup (you could make your own -- grind unsalted peanuts with a little oil and a pinch of salt until smooth or use any nut butter – I had organic peanut butter to hand). Smooth the tops so it sits slightly below the chocolate. Spoon chocolate over the top of the peanut butter to seal. Place back in the freezer for about 10 minutes.
Remove from tray. Store in the fridge.
Because it is dark chocolate and no added sugar peanut butter, they are actually somewhat healthy.
Makes about a dozen.