Use a ladle to fill the plastic chocolate candy mold of your choice ( I used a small Bon Bon shape), with the tempered bittersweet chocolate. Tap the mold on the counter to encourage the air bubbles to depart. When the mold is full, empty it into the bowl of chocolate. The inside of each cavity should be evenly coated with chocolate. Scrape the mold clean with an offset spatula and place it upside down on a wire rack placed over a baking sheet. Once the chocolate starts to harden, about 5 minutes, scrape the edge clean again, with a chef's knife. When the chocolate sets, it shrinks or retracts from the sides of the mold. A clean edge will keep it from sticking and cracking as it shrinks. You can place the mold in the refrigerator for several minutes to help the chocolate to harden. Repeat with as many candy molds as you would like.
For the filling: Place the coconut milk in a pan and bring to a boil. Stir in the corn syrup, coconut rum and rum. Place the white chocolate and in a large mixing bowl. Pour the hot coconut milk over the chocolate in the bowl and mix thoroughly. Stir in the shredded coconut. Allow the mixture to come to room temperature (though it should still be soft enough to pipe). Place the mixture in a piping bag and fill each chocolate cavity with the coconut mixture, to just shy of the top of the cavity. Allow this to set until the mixture hardens, about 2 hours.
Use an offset spatula to cover the openings of each cavity with more tempered bittersweet chocolate. When the chocolate has begun to set, use an offset spatula to scrape away the excess chocolate. Allow the chocolate to set completely. Overturn the mold and give it a quick rap on the counter. The chocolates will release from the mold. They are ready to serve.
How to Temper Chocolate
Chocolate is tempered so that after it has been melted, it retains its gloss and hardens again without becoming chalky and white (that happens when the molecules of fat separate and form on top of the chocolate). There are a variety of ways to temper.
One of the easiest ways to temper chocolate is to chop it into small pieces and then place it in the microwave for 30 seconds at a time on high power until most of the chocolate is melted. Be very careful not to overheat it. (The temperature of dark chocolate should be between 88 and 90 degrees F, slightly warmer than your bottom lip. It will retain its shape even when mostly melted. White and milk chocolates melt at a temperature approximately 2 degrees F less because of the amount of lactose they contain.) Any remaining lumps will melt in the chocolate's residual heat. Use an immersion blender or whisk to break up the lumps. Usually, chocolate begins to set, or crystallize, along the side of the bowl. As it sets, mix those crystals into the melted chocolate to temper it. A glass bowl retains heat well and keeps the chocolate tempered longer.
Another way to temper chocolate is called seeding. In this method, add small pieces of unmelted chocolate to melted chocolate. The amount of unmelted chocolate to be added depends on the temperature of the melted chocolate, but is usually 1/4 of the total amount. It is easiest to use an immersion blender for this, or a whisk.
The classic way to temper chocolate is called tabliering. Two thirds of the melted chocolate is poured onto a marble or another cold work surface. The chocolate is spread out and worked with a spatula until its temperature is approximately 81 degrees F. At this stage, it is thick and begins to set. This tempered chocolate is then added to the remaining non-tempered chocolate and mixed thoroughly until the mass has a completely uniform temperature. If the temperature is still too high, part of the chocolate is worked further on the cold surface until the correct temperature is reached. This is a lot of work, requires a lot of room, and makes a big mess.
A simple method of checking tempering, is to apply a small quantity of chocolate to a piece of paper or to the point of a knife. If the chocolate has been correctly tempered, it will harden evenly and show a good gloss within a few minutes.
From Dessert Circus, Extraordinary Desserts You Can Make At Home by Jacques Torres.