Peanut butter & chocolate cookie sandwich cookies

1/2 c  REESE'S Peanut butter Chips
      3 tb Plus
    1/2 c  butter or margarine,
           -softened and divided
  1 1/4 c  Sugar, divided
    1/4 c  Light corn syrup
      1    Egg
      1 ts vanilla extract
      2 c  Plus
      2 tb All-purpose flour, divided
      2 ts Baking soda
    1/4 ts Salt
    1/2 c  HERSHEY'S Cocoa
      5 tb butter or margarine, melted
           Additional sugar
     24 lg Marshamllows
 
  Heat oven to 350'F. In small saucepan over very low heat, melt peanut
  butter chips and 3 tablespoons softened butter. Remove from heat; cool
  slightly. In large mixer bowl, beat remaining 1/2 cup softened butter and 1
  cup sugar until light and fluffy. Add corn syrup, egg and vanilla; blend
  thoroughly. Combine 2 cups flour, baking soda and salt; add to butter
  mixture, blending well. Remove 1 1/4 cups batter and place in a small bowl;
  with wooden spoon, stir in remaining 2 tablespoons flour and peanut butter
  chip mixture. Blend cocoa, remaining 1/4 cup sugar and melted butter into
  remaining batter. Refrigerate both batters 5-10 minutes or until firm
  enough to handle.
  
  Roll both doughs into 1" balls; roll in additional sugar. Place on
  ungreased cookie sheet. Bake 10-11 minutes or until set. Cool slightly;
  remove from cookie sheet to wire rack. Cool completely. Place 1 marshmallow
  on flat side of 1 chocolate cookie. Microwave at MEDIUM (50%) 10 seconds or
  until marshmallow is softened; place a peanut butter cookie over
  marshmallow, pressing down slightly. Repeat with remaining marshmallows and
  cookies. Serve immediately.
  
  Makes about 2 dozen sandwich cookies.