Place the peanut butter, unsalted butter, salt and vanilla in a bowl. Use a mixing spoon or a hand-held mixer to mix the ingredients to form a smooth paste.
Add the confectioner’s sugar - a little at a time, and mix it into the peanut butter, until well mixed. (The mix will get stiffer as you add confectioner’s sugar. If you need to, use clean, dry hands to knead the mix to make sure everything is well combined).
If you find the peanut butter mix to be too soft, add some extra confectioner's sugar (up to an additional 1/2 cup) to get the consistency you like.
Using a 2 tbsp cookie scoop - portion out the peanut butter mixture. Roll each piece into a smooth ball and keep it on a parchment paper-lined baking tray. Repeat with all of the peanut butter mix.
Insert a toothpick into each peanut butter ball. Refrigerate for about 2 hours (or longer), until chilled.
Once the peanut butter balls are chilled and are ready to be dipped, prepare the chocolate dip.
Place the chocolate in a dry, clean, microwave-safe glass bowl. Microwave in 20-second intervals, stirring in between until most of the chocolate chips have melted, but some lumps are remaining. Then stir the chocolate until all of the chocolate has melted, and is completely smooth. This melting technique prevents the chocolate from getting too hot.
Using a toothpick, dip each peanut butter ball into the chocolate, and swirl to coat evenly. Make sure NOT to cover the top of the peanut butter ball, so that some of the peanut butter peeks through the top.
To get rid of excess chocolate - hold up the dipped peanut butter ball by the toothpick, and gently rotate it. Place the dipped peanut butter ball back on the parchment paper-lined baking tray. Repeat with the remaining peanut butter balls. Then, remove the toothpicks, and use an offset spatula or the flat part of a butter knife to smooth the toothpick holes over. Return the peanut butter balls to the fridge for a few minutes to set.