Gently mix cereals, nuts and pretzels in a large bowl. In a 2 cup glass measuring cup add brown sugar, butter and Karo syrup. Microwave for 2 minutes until melted, stirring well after 1 minute. Add baking soda to the caramel sauce and mix well. Pour sauce over cereal mixture and mix gently until cereal is completely coated.
Pour coated cereal mixture onto a jelly roll pan and bake at 250 degrees for 40-45 minutes, stirring every 15 minutes. Be SURE to stir so that the chex mix won’t get stuck together.
Cool completely and add craisins and M&Ms.
Makes about 14 cups of Cranberry-Caramel Chex Mix.