Preheat an oven or toaster oven to 300°F. Place the coconut flakes in a single layer on a parchment-lined baking sheet and toast in the oven for 3-5 minutes or until golden brown on the edges. Take them out and cool to room temperature.
One of the keys to melting chocolate evenly is to cut the chocolate bars into small pieces—don’t just break them up into large squares. Starting at one of the corners, use a sharp serrated knife to cut the chocolate into small shards on the diagonal. This step might seem like a chore, and you’re gonna have to flex your muscles, but the chocolate will melt faster and more evenly once it’s properly chopped.
Place the chocolate shards into a glass mixing bowl. You have two options for melting the chocolate: use a double boiler or a microwave. Most folks don’t own a double boiler, but you can make your own by grabbing a metal or glass bowl that fits snugly in a medium saucepan. Fill the saucepan with about two inches of water and bring it to a simmer. Place the bowl on top of the saucepan, making sure that the water never touches the bottom of the bowl.
While maintaining the water at a simmer, stir the melting chocolate until it’s smooth. Be patient and don’t overheat the chocolate—it can turn grainy if the temperature goes above 115°F. (You can check the temperature with this nifty thermometer.)
For those of you who use a microwave oven, you can melt the chocolate by zapping it on high for 30 seconds, and stirring well to evenly distribute the heat. Repeat two more times, and stir until smooth. If the chocolate’s not totally melted after a minute and a half, repeat in 15 second increments. Be careful not to overcook it!
While the chocolate is melting, line a rimmed baking sheet with parchment paper.
Pour the melted chocolate onto the parchment paper, and using an offset or silicone spatula, spread it thinly and evenly into a rough rectangle, keeping the chocolate layer about ⅛- to ¼-inch thick. Dark bark is supposed to be rustic, so don’t stress out if it’s not totally uniform.
Grab your toppings, and sprinkle on the macadamia nuts, toasted coconut, and dried cranberries. Once the chocolate is decorated, I gently push down the toppings that look like they need a little help getting stuck in the chocolate.
Place the tray in the fridge for at least 30 minutes or until hardened. Once the dark bark has solidified, break or cut it into pieces.
If you’re going to eat the dark bark by yourself, you can store it in a sealed container in the fridge for up to a week.