In a large bowl, cream the butter, peanut butter, and sugars until light
and fluffy. Beat in egg and vanilla.
In a smaller bowl, combine flour and baking soda.
Gradually add the dry mixture to the creamed mixture and mix well. Cover and refrigerate for 1 hour or until easy to handle.
Roll dough into 1-1/4-inch balls. Press a miniature peanut butter cup into
each; reshape balls.
Place 2 inches apart on ungreased baking sheet.
Bake at 350 degrees F for 12-15 minutes or until edges are lightly browned.
Cool for 2 minutes before removing from pans to wire racks.
For drizzle,melt chocolate chips, peanut butter, and shortening in a microwave (or in a double boiler). Stir until smooth. Drizzle over cooled cookies. (I allowed my mixture to cool slightly and then put it into a Ziploc bag. I snipped off a tiny portion of the corner of the bag so I could drizzle the cookies.)