optional:tiny pinch of salt, if using unsalted peanut butter
Line a 12 cup standard size muffin tin with paper liners.
Place 1 cup of the chocolate chips in a microwave safe bowl, microwave for 1 minute, stir, then another minute and stir until melted and smooth. If you do not have a microwave, you can use the double broiler method to melt them.
Scoop about 1/2 a tablespoon melted chocolate, and place it in each liner. Use a small spoon to spread it around and up the sides just a little bit. Use your fingers on the other hand to stabilize the cup while you do this. Place the pan in the freezer for 10 minutes.
While the chocolate hardens in the freezer, add the peanut butter and powdered sugar to a bowl and mix with a spoon or fork until well combined and a sort of dough is formed. Taste for sweetness, and add more sugar if desired. If using unsalted peanut butter, add a tiny pinch of salt.
Remove the pan from the freezer. The chocolate should be quite firm and not melty anymore. Place a tablespoon of the peanut butter mixture on top of the chocolate in each cup, and press down a bit with your hands. It does not need to be flattened completely. Place the pan in the freezer for 10 minutes.
Melt the other cup of chocolate chips as you did before. Scoop 1/2 tablespoon on top of the peanut butter and spread immediately with a small spoon. Because the peanut butter was in the freezer, the chocolate will harden quickly. Place in the freezer for 10 minutes to set.
Enjoy! You can store peanut butter cups in the refrigerator, or at room temperature for a softer candy.
Many brands of chocolate chips are vegan, simply check the ingredients list for milk fat, butter oil or "contains milk".
Instead of chocolate chips, you can also use vegan chocolate bars, which may be easier to find depending on where you live. You will probably need 3 bars, or about 12 ounces total. Simply chop and melt the bar like you would the chocolate chips.