Prepare the Peanut Butter Layer

1. Mix the Ingredients: In a medium-sized bowl, combine the peanut butter, powdered sugar, vanilla extract, and softened butter. Stir until smooth and well-combined.
2. Spread the Peanut Butter Layer: Lay out a sheet of wax paper or parchment paper. Spread the peanut butter mixture into a thin, even layer about 1/4-inch thick.

Chill the Peanut Butter Layer

1. Chill to Set: Place the peanut butter layer in the fridge for 15-30 minutes, or until firm and easy to roll up.

Prepare the Chocolate Coating

1. Melt the Chocolate: In a microwave-safe bowl, heat the semi-sweet chocolate chips and vegetable oil in 30-second intervals, stirring between each until fully melted and smooth.

Assemble the Pinwheels

1. Roll It Up: Once the peanut butter layer is chilled and firm, carefully peel it off the parchment paper and gently roll it up into a log shape.
2. Coat with Chocolate: Dip each rolled pinwheel into the melted chocolate, covering it completely. Use a fork to lift the candy out of the chocolate and tap gently to remove any excess.
3. Set the Pinwheels: Place the coated pinwheels back onto a sheet of parchment paper. Allow the chocolate to set by refrigerating them for 15 minutes.