In large bowl, combine cereal, oats and raisins; set aside.
In small saucepan, combine brown sugar and corn syrup.
Bring to a boil, stirring constantly.
Remove from heat.
Stir in peanut butter and vanilla; blend until smooth.
Pour over cereal mixture; mix well.
Press into ungreased 13 x 9-inch pan.
Cool; cut into bars.