Line a baking sheet with parchment paper or a silicone baking mat. Set it aside to prepare for shaping the balls.
Using a stand mixer with a paddle attachment or a hand mixer, beat the softened butter on medium-high speed until smooth and creamy, about 2 minutes.
Add the peanut butter and continue mixing for another minute until well blended.
Reduce speed to low and add confectioners’ sugar, vanilla extract, and salt. Mix for 2 minutes until a soft, crumbly dough forms.
Scoop and roll the dough into balls, about 1 tablespoon each. If sticky, refrigerate for 15 minutes or dust hands with powdered sugar. Place on the prepared baking sheet.
Chill the rolled balls in the refrigerator for at least 1 hour to firm them for dipping.
Melt the chocolate and oil in a microwave-safe bowl or double boiler. Let it cool for about 6 minutes before dipping.
Dip each chilled ball into the melted chocolate using a fork or spiral dipping tool. Tap to remove excess chocolate and place on a clean sheet.
Add sprinkles or sea salt while the coating is still wet, if desired.
Refrigerate the dipped balls for 30 minutes or until the chocolate is fully set.
Store in an airtight container at room temperature for 2 days, in the fridge for 2 weeks, or freeze for up to 3 months.