Mix all of the ingredients for the peanut butter filling in a bowl until you get a smooth and chunk-free mass.

Transfer the mass into a silicone mold for candy making, such as this one. Leave a bit of space on top of the peanut butter filling for the chocolate bottom. Place the mold into your freezer and chill for at least 20-30 minutes before proceeding to the next step.

Melt the chocolate using a double boiler and pour part of the chocolate over the partly frozen peanut butter filling (the chocolate shouldn't be too thick nor to thin, aim for approx. 5mm or 0.2"), then place the silicone mold back in the freezer and freeze until solid.

Reheat the chocolate you melted before. Once the naked peanut butter bars are solid enough to be pressed out of the silicone mold without breaking, pop them out and place them on a baking rack with parchment paper placed beneath it. Pour the chocolate over the peanut butter bars, making sure to cover them completely.

Optional: Add chopped peanuts onto the top of the peanut butter bars while the chocolate is still liquid for decoration.

Chill the chocolate covered peanut butter bars in your fridge until the chocolate hardened up. Once the chocolate is hard, you can enjoy them but I'd wait a bit more until the peanut butter filling isn't frozen anymore.

Store covered with plastic wrap or in an air-tight container and enjoy for up to a week.