1. Heat oven to 350°F.
2. In medium bowl, combine oats, flour, baking powder, baking soda and salt; mix well.
3. In large bowl, beat together peanut butter and butter with electric mixer on medium speed until smooth. Beat in granulated and brown sugars, eggs and vanilla until blended. Beat in flour mixture just until blended.
4. On ungreased baking sheets, drop dough by level tablespoonfuls 2 inches apart. Bake 13 minutes or until golden. Immediately press chocolate firmly in center of each cookie. Remove cookies to wire rack to cool completely.
Makes about 72 cookies.