In a small mug, whisk 1/4 of the soy milk with the arrowroot powder and set aside.
In a medium saucepan, combine the rest of the soy milk with the soy creamer, sugar and cocoa powder. Over medium heat, whisk until blended. Add the chocolate chips and continue to cook over medium heat, stirring constantly until the chocolate chips are fully melted. Increase the heat and bring to a slow boil.
Once the batter has started to boil, remove from the stove immediately and mix in the arrowroot slurry. Add the vanilla extract, whisking well. Store covered in the fridge for at least four hours (or until chilled) before processing. (I prefer to chill it overnight, just to be safe.)
In a microwave safe bowl, combine the peanut butter and powdered sugar. Heat on high for 30 seconds and then stir until fully blended, heating the peanut butter in additional 15-second increments as necessary. Add more or less sugar to taste. When done, transfer to a lidded container and store in the fridge for four hours or more. Keep stored in the fridge until ready for use.
When you’re ready to make the ice cream, process the chocolate batter according to your ice cream machine’s directions. Toward the end of the cycle, drop in the peanut butter by the spoonful and add the chocolate bark, too. If you don’t have enough room – or would prefer to have more control over the size of the pb and chocolate bits – you can instead mix in the peanut butter and chocolate bark after the chocolate ice cream is done processing. (This is usually how I do it!)
Transfer to a lidded container and chill in the freezer for an hour or so before serving. Or enjoy immediately as soft serve.