Preheat the oven to 325F. Line a baking sheet with parchment paper.
In a large bowl, whisk together the almond butter, maple syrup, oil, and vanilla until smooth.
Add the chex, oats, nuts/seeds, cinnamon, and salt and mix with a rubber spatula until evenly combined. Transfer to the baking sheet and spread out into an even layer.
Bake for 15 minutes. Meanwhile, to make the cinnamon sugar, in a small microwavable bowl (or use the same large bowl if it’s microwavable), melt the butter. Whisk in the sugar and cinnamon until combined.
Pour this mixture all over the granola and toss to coat as best you can. Spread out into an even layer and bake for 25 more minutes.
Let cool completely before eating and/or storing. This will allow it to get crunchy.