1. Heat oven to 350°F. Beat peanut butter and butter in large bowl until well blended. Add granulated sugar and brown sugar; beat until fluffy. Add egg, milk and vanilla; beat well. Stir together 1/2 cup oats, flour, baking soda and salt; gradually beat into peanut butter mixture.
2. Shape dough into 1-inch balls. Roll in remaining oats; place on ungreased cookie sheet. Flatten cookies with tines of fork to form a crisscross pattern.
3. Bake 10 to 12 minutes or until lightly browned. Cool slightly; remove from cookie sheet to wire rack. Cool completely.
4. Place chocolate chips and 1 teaspoon shortening in medium microwave-safe container. Microwave at MEDIUM (50%) 30 seconds; stir. If necessary, microwave at MEDIUM an additional 10 seconds at a time, stirring after each heating, until chocolate is melted and smooth when stirred. Drizzle over cookies. Repeat procedure with peanut butter chips and remaining 1 tablespoon shortening. Allow drizzles to set.
Makes about 48 cookies.