In a large bowl, beat the peanut butter and softened salted butter together until smooth and well combined.
Stir in the powdered sugar until a firm, moldable dough forms.
Use a small cookie scoop or a tablespoon to portion the dough into roughly 1-inch balls.
Press each ball onto a mini pretzel to attach, then place the pretzel side down on a baking sheet lined with wax paper or parchment.
Cover the baking sheet with plastic wrap and refrigerate for at least 1 hour to firm up the peanut butter centers.
Place chocolate chips and the oil in a microwave-safe bowl and heat in 20-second intervals, stirring between each, until the chocolate is smooth and fully melted.
Dip each peanut butter-topped pretzel into the melted chocolate to coat the peanut butter portion, then return to the prepared sheet with the pretzel side down.
Chill the dipped bites in the refrigerator until the chocolate is set, then serve.