Line a plate or chopping board with a piece of parchment paper. Set aside.
In a medium-size mixing bowl, add fresh runny peanut butter along with coconut flour and erythritol.
Combine with a spatula at first, then use your hands to knead the dough. You want all the ingredients to be evenly combined. It should take no more than 1 minute to form a dough ball that holds together. It should be soft, slightly sticky, and shiny.
Divide the dough into 18 even pieces.
Roll each piece into a ball, and place each ball onto the plate covered with parchment paper. The dough is soft and will slightly flatten. That is ok! Keep rolling the balls, and make sure you leave a 1-thumb space between each ball to prevent them from sticking together.
Place the plate in the freeze for 12 minutes. This step will firm up the balls slightly. This will allow you to shape beautiful balls, and it makes it easier to dip the balls into the melted chocolate. Don't skip this!
Remove from the freezer and reshape the balls that may have flattened too much.
Place the plate back in the freezer for 12 minutes.
Meanwhile, prepare the chocolate dipping sauce.
Add the sugar-free dark chocolate pieces with the coconut oil into a microwave-safe bowl.
Microwave by 30-second bursts, stirring between each until the chocolate is fully melted and shiny.
Remove the plate with the peanut butter balls from the fridge. They must be half-frozen, hard on the sides, and still soft in the center. If too soft, keep them in the freezer for an extra 5-10 minutes.
Plant a toothpick in the center of the peanut butter ball.
Dip the peanut butter ball into the melted chocolate using your toothpick as a tool to gently roll the ball into the chocolate. As the peanut butter balls are slightly frozen and your chocolate is hot, the shell should harden fast.
Bring the peanut butter ball back to the plate covered with parchment paper.
Repeat the chocolate dipping steps until the 18 balls have been covered with chocolate.
Bring the plate back to the freezer to set the chocolate shell. It should take about 3-5 minutes.
Store the balls in an airtight container in the fridge, don't overlap to prevent them from sticking together. They store for up to 2 weeks. Don't store at room temperature, or they get really soft.
Freeze in a ziplock bag or airtight container and defrost at room temperature 3-4 hours before eating. They can also be eaten half frozen.
Replace peanut butter with the same quantity of sunflower seed butter.