In a medium bowl, mix the pretzel crumbs, melted butter, and granulated sugar until well combined.
Press the mixture firmly into the bottom of a 9-inch pie pan to form the crust.
Bake at 350°F for 10 minutes, then remove and let cool completely.
In a large mixing bowl, combine the creamy peanut butter and powdered sugar. Mix until smooth and creamy.
In another bowl, whip the heavy cream and vanilla extract until stiff peaks form.
Gently fold the whipped cream into the peanut butter mixture until fully combined.
Spread this filling evenly over the cooled pretzel crust.
In a small saucepan, melt the chocolate chips and vegetable oil over low heat, stirring until smooth.
Pour the melted chocolate over the peanut butter filling, spreading it evenly.
Refrigerate the pie for at least 4 hours, or until set.
Slice and serve chilled.
