COMBINE cereal, pretzels and nuts in large bowl.
Distribute evenly between two 13 x 9-inch baking pans or one shallow roasting pan.
COMBINE brown sugar, butter and corn syrup in medium, heavy-duty saucepan.
Bring to a boil, stirring constantly, over medium heat.
Boil, without stirring, for 5 minutes.
Remove from heat; stir in vanilla and baking soda.
Pour evenly over cereal mixture; stir until coated.
BAKE in preheated 250° F. oven, stirring every 15 minutes, for 45 minutes.
Cool completely in pan(s), stirring frequently to break apart mixture.
Stir in morsels and raisins.
Store in airtight container.