In a heat-proof bowl, microwave the coconut milk, oil, maple syrup (if using) and matcha powder for 30 seconds, or until the coconut milk bubbles. Stir in the chocolate and place a bowl or lid over the top of the bowl to lock in the heat. Let rest for 5 minutes, then mix until smooth. (If there are still chocolate lumps, zap for 10 more seconds in the micro. I had to do this twice).
Place the bowl in the fridge until the chocolate is firm, about 3 to 4 hours. (Dana over at Minimalist Baker has a great tip: stick a knife through the center of the chocolate mixture and make sure it comes out clean).
Using a melon baller or teaspoon, portion the chocolate and roll in your hands to form smooth, round balls. The colder the chocolate is, the easier it will be to roll. Pop the bowl back in the fridge every 5 minutes if you need to. Also, keep a bowl of water handy for your chocolatey paws!
Arrange your toppings on separate plates and roll your balls in them, pressing to adhere. For the matcha, you can also just use a sift (looks prettier this way).
Return to the fridge to firm up further, about 20 minutes. Or store them for later—they last up to one week!