Peanut Butter and Jelly Thumbprint Shortbread Cookies

1 cup butter, softened

⅔ cup white sugar

½ teaspoon vanilla extract

2 cups all-purpose flour

½ cup grape jelly

½ cup creamy peanut butter

1 ½ teaspoons vegetable oil

Preheat an oven to 350 degrees F (175 degrees C); line a baking sheet with parchment paper.

Beat the butter and sugar with an electric mixer in a large bowl until smooth; add the vanilla and continue to beat. Mix in the flour mixture until just incorporated. Roll dough into 1 1/2-inch balls and arrange on prepared baking sheets. Make a small hole in the center of each ball, using your thumb and finger; fill the holes with grape jam.

Bake in the preheated oven until lightly browned, about 14 minutes; allow to cool on baking sheet for 1 minute.

Put the peanut butter in a microwave-safe bowl, and cook in a microwave oven until soft for 10 - 30 seconds, checking every 10 seconds. Be careful not to overheat the peanut butter; do not let it bubble. Stir the vegetable oil through the heated peanut butter; drizzle over the warm cookies.