Prepare two sheet pans with parchment paper. Add cereals, pretzels, honey grahams, nuts and coconut to a very large mixing bowl.
Add butter to a large saucepan over medium heat. Once melted add corn syrup and sugar and stir well to combine. Bring to a boil, stirring continuously. Once the mixture comes to a FULL rolling boil over medium heat, cook, stirring constantly, for 2-3 minutes.
Remove from heat immediately and stir in vanilla and baking soda. Slowly pour syrup over the chex mix and use a wooden spoon to gently stir to coat the cereal
Pour cereal out onto prepared baking sheet and allow to cool before eating.
