Begin by processing 2 cups of unsalted pretzel sticks and 1 cup of old-fashioned rolled oats in a food processor. Pulse until they resemble coarse crumbs, about 30 seconds.

In a small saucepan over low heat, melt 1/2 cup of Concord grape jelly until it turns golden and smooth, stirring frequently, approximately 3-5 minutes. Transfer it to the pretzel-oat mixture.

Allow the crust mixture to cool to around 70°F (21°C) for about 10 minutes.

In a large mixing bowl, combine 1 1/2 cups of chunky peanut butter with the cooled crust mixture. Stir until well blended, incorporating 1 teaspoon of vanilla extract.

Press the pretzel mixture firmly into a 7-inch pie tin, using your fingers or the bottom of a measuring cup.

Spread the creamy peanut butter filling evenly over the pressed pretzel crust.

Refrigerate the pie at 38°F (3°C) for at least 15 minutes.