Note: To make these chocolates, you will need a tray of chocolate molds (I like the silicone kind) and a sugar thermometer (ideally digital, but any kind will do—I’ve made them, using both). —Skye | From My Dining Table
Set out a tray of chocolate molds (I find that silicone molds work best). Sift the cocoa powder and coffee directly into a saucepan over low heat. Immediately add the the milk and sugar, stirring constantly until the sugar has dissolved, about 2 to 3 minutes.
Stirring constantly, slowly drizzle in the cream, turn up the stove to medium heat, and slowly bring the coffee-cream mixture to the boil. When the cream begins to bubble, allow it to boil for 2 to 3 minutes, then remove it from the heat and set it to one side to cool and thicken. This will be the filling for your chocolates.
Set one-third of the chocolate to one side, then toss the other two-thirds into a small heatproof bowl. Place the bowl over a saucepan of simmering water (or into a double boiler) over medium heat and allow the chocolate to melt slowly. Be very careful not to let the water touch the bottom of the bowl, as too much direct heat will cause the chocolate to spoil and burn.
When the chocolate is melted, test it with your candy thermometer. When it reaches 130 to 145º F (55 to 58º C), take it off the heat. Toss the rest of the chopped chocolate into the bowl with the melted chocolate and stir vigorously to melt it all together. If you find that there are still a few whole, unmelted chunks of chocolate at this stage, remove them from the bowl and discard them before setting the melted chocolate back on the heat—the chunks will make the chocolate sticky rather than luscious and smooth, as you want it to be. When it reaches a temperature of 80º F (27º C), set it back onto the heat over the saucepan of simmering water. When the chocolate returns to a temperature of 87 to 90º F (31 to 32º C), it is ready to work with.
Use a pastry brush to paint a thin layer of the melted chocolate in the chocolate molds, being careful to coat each mold thoroughly with chocolate. Transfer the tray to the refrigerator and let harden and chill for 15 to 20 minutes. Repeat this process a second time to create a second layer of chocolate, leaving them to chill in the refrigerator for another 15 to 20 minutes, or until hardened.
When the shells are hard and solid, you can fill them: Spoon the coffee-cream mixture into the chocolate-coated molds up to roughly the 3/4 mark. Refrigerate them for an additional 5 minutes to allow the cream filling to harden then brush a layer of melted chocolate over the top to seal them. Set the tray in the refrigerator for another 15 to 20 minutes, until the chocolates are thoroughly hardened. Gently remove the chocolates from their molds. If you have any leftover coffee cream, you can store it in the refrigerator in an airtight container for up to 4 days and use it as a filling in cakes or drizzled over ice cream.