Mix the first 5 ingredients into a extra large bowl.
Bring brown sugar and light corn syrup to a boil for 2 minutes, remove from heat, add the vanilla and peanut butter and stir well until all is blended.
Pour brown sugar mixture into dry Cereal and Oats mixture. Stir quickly as it gets more gooey as it cools. Wait about 2-3 minutes, then add the chocolate chips and nuts....coat well.
Using a 12X18 jelly roll pan, dump Granola mixture into buttered (or no stick spray)pan. You can use Wax Paper or a good plastic spoon/spatula for pressing Granola into prepared pan evenly. Put in fridge to firm up a bit, then cut into your desired pieces. These are absolutely scrumptious....Enjoy!