First, open paper bags and place one inside of the other. Pour Chex cereal and pecans into bags. Set aside. Cover table or counter top with wax paper and spray with non-stick cooking spray. In a large kettle, combine and stir cinnamon and brown sugar until well mixed. Add butter and corn syrup and bring to a boil on the stove, stirring frequently as not to burn. When everything is all melted and incorporated, take off heat and add vanilla and baking soda. Stir until foamy. Pour over the double bagged Chex. Roll down top and shake well. Microwave for 2 minutes and shake well. Microwave for 2 more minutes and shake again. Make sure to turn the bag on all sides each time you shake to spread the caramel. Open bag and check to make sure the caramel is spread evenly throughout the Chex. If not, shake again. However, you should be able to dump the Chex onto the sprayed wax paper. Spread the mix as thin as possible. Pour white chocolate chips into zip-loc bag. Place in microwave for 20 seconds and use fingers to mix. Repeat until white chocolate is melted. Cut a small corner off of the bag and drizzle white chocolate over cereal mix. Let stand until chocolate sets. Serve immediately, or package in your favorite containers to share as gifts.