In a large mixing bowl, beat peanut butter and powdered sugar until smooth. Roll into 30 3/4 in balls. Cover & refrigerate for 30 min.

Meanwhile, in another mixing bowl, cream butter, peanut butter, & sugars until light & fluffy. Beat in egg white and vanilla.

Combine flour, cocoa and baking soda; gradually add to creamed mixture until blended. Roll into 30 1 1/2 in balls.

Using floured hands, flatten chocolate balls and shape one around each peanut butter ball, sealing edges. Place 2 in apart on a greased baking sheet.

Flatten with glass dipped in sugar. Bake at 375° for 7-9 min or until cookies are set and tops are cracked. Cool 1 min before removing to wire racks.

For icing, in a small bowl, beat shortening and sugar until smooth. Beat in vanilla and enough milk to reach spreading consistency. Spoon into a resealable plastic bag; cut small hole in corner of bag. Pipe icing over cookies in a zigzag pattern.