In a large bowl, mix together the peanut butter, maple syrup and melted coconut oil with a large spoon. When well mixed, add in the rice crisp cereal.
Using a spoon, scoop the mixture out onto a parchment paper lined baking sheet, in 24 uniform sized balls/chunks. *Note: the mixture will be very sticky and will stick to your hands if you use them to roll these out.
Place the baking sheet with the crisps into the freezer until set up well, about 20 to 30 minutes. At this point, if you would like to use your hands and shape them into more of a ball, you can do so.
Melt the dark chocolate chips in a medium saucepan over medium low heat. Use a spoon to stir continuously as the chocolate is melting. Once it has completely melted, turn the fire off and scoop about one teaspoon of melted chocolate over the top of each crisp. Top each crisp with a pinch of sea salt flakes, and place the baking sheet with cookies back into the refrigerator to continue setting up for another hour or more. Store in the refrigerator or freezer until ready to be enjoyed.