Place coconut milk, cacao powder and maple syrup in a medium saucepan. Heat the mixture over medium heat, whisking constantly until it comes to a simmer. Remove from heat and whisk in peanut butter. Place a fine mesh sieve over a bowl and pour chocolate mixture through the sieve. Cover the bowl tightly and place in the refrigerator to chill for about 2 hours. Freeze mixture in your ice cream maker according to manufacturer’s directions. Serve.