COOKIES: Combine peanut butter an shortening. Beat until well blended. Add brown sugar. Beat until well blended. Beat in eggs. In separate bowl, combine flour, baking powder and salt. In another bowl, combine milk and vanilla. Add flour mixture and milk mixture alternately to creamed mixture until well blended. Spread into greased 15x10x1 inch pan. Bake at 350 for 18-20 minutes.
FROSTING: Beat together peanut butter and shortening. Add confectioners' sugar and milk slowly until well blended and fluffy. Spread on cooled cookies.
DRIZZLE: Melt chocolate chips and Crisco. Drizzle over frosting. Let chocolate set.