1. Melt the chocolate in a clean, dry bowl set over a pan of barely simmering water. If you want to temper the chocolate (see above.) While the chocolate is melting, gather and prepare any ingredients you want to put on the bars.
2. Once the chocolate is melted, (and tempered, if tempering the chocolate), remove the bowl from the pan and wipe the moisture off the bottom of the bowl.
3. Pour or spoon a layer of chocolate into your molds. Rap them on the counter a few times to distribute the chocolate evenly and release any air bubbles, then working quickly, top with any kinds of nuts, dried fruits, or other ingredients that you wish and press them in slightly.
(You can also stir ingredients into the chocolate, such as toasted nuts, seeds, crisped rice cereal, snipped marshmallows, or other ingredients, then pour the mixture into the molds.)
4. Immediately put the bars in the refrigerator until firm. If tempered chocolate is used, it shouldn’t take more than five minutes for them to firm up. Otherwise the chocolate will take longer.
Tempered bars can be stored at room temperature for up to one month; if using regular melted chocolate, store the bars the refrigerator until ready to eat.