Heat oven to 350ºF.
Beat peanut butter and butter in large bowl with mixer until creamy. Add sugars; beat until light and fluffy. Blend in eggs and vanilla.
Mix oats, flour and baking soda. Add to peanut butter mixture; beat until blended. Stir in chocolate.
Drop teaspoonfuls of dough, 1 inch apart, onto baking sheets.
Bake 10 to 12 min. or just until centres are set. Cool on baking sheets 3 min. Remove to wire racks; cool completely.