Peanut Butter Balls are sweet treats that are made with creamy peanut butter and coated with a layer of melted, semi-sweet chocolate.
Scoop out the peanut butter mixture with a one tablespoon scoop and roll it into a ball. Place it on the parchment-lined baking sheet. Repeat with the remaining peanut butter mixture.
While the peanut butter balls are in the freezer, melt the chocolate. Add the chocolate pieces and oil to a microwave-safe bowl. Heat in 20-second increments, stirring after every 20 seconds, until the chocolate is melted and creamy. Let it sit for about 5 minutes to cool before dipping the peanut butter balls.
Remove the peanut butter from the freezer. (It's helpful to only remove a few peanut butter balls at a time to prevent melting.) Working one at a time, gently drop the balls into the melted chocolate, making sure they are completely covered in chocolate.
Using a fork, lift out the chocolate-covered peanut butter balls. Use a toothpick or another fork to slide the peanut butter balls onto the parchment-lined baking sheet. (You may need to reheat the chocolate to keep it a thin mixture.) Add the nuts at this point, if using.
Place in the refrigerator for about 30 minutes, or until the chocolate has set.