Step 1

In the bowl of a stand mixer with a paddle attachment (or in a large bowl using a handheld mixer), beat the peanut butter and butter until creamy (about 2 minutes).

Step 2

Working 1/2 cup at a time, add the confectioners' sugar. Beat on low for about a minute and then increase to high until smooth and creamy (about 3 minutes).

Step 3

Cover the bowl with plastic wrap and place the peanut butter mixture in the refrigerator to chill for one hour, up to 24 hours.

Step 4

When ready, line a baking sheet with parchment paper and remove the chilled peanut butter mixture from the refrigerator.

Step 5

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.

Step 6

Place the peanut butter balls in the freezer to chill while you prepare the chocolate coating.

Step 7

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.

Step 8

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.

Step 9

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.

Step 10

Place in the refrigerator for about 30 minutes, or until the chocolate has set.

Step 11

Store candies in the refrigerator in an airtight container for up to 2 weeks.