Preheat the oven or pellet smoker to 350 F. Line a baking sheet with parchment paper or aluminum foil and set it aside.
Prep all the ingredients so they are ready to go, this recipe needs to move quickly before cooking begins.
Place the peanut butter crackers into a large mixing bowl and set it aside.
In a pot over medium heat, add the butter and let it fully melt.
Whisk in the brown sugar. Continue to whisk until it fully dissolves and mixes completely with the butter, this will take a few minutes.
Once the brown sugar mixture is fully combined, continue to slowly whisk and let it bubble softly for 2 minutes.
Remove it from the heat and add the cinnamon and vanilla and whisk it in.
Pour the brown sugar mixture over the peanut butter crackers and quickly fold the mixture over so it evenly coats all the crackers.
Place the peanut butter crackers onto the parchment paper lined baking sheet and spread them out in a single layer.
Smoke or bake the crackers for 15 minutes. The sugar mixture should begin to caramelize and harden onto the crackers and bubble slightly.
While the crackers are baking or smoking, mix the remaining cinnamon and granulated sugar together in a small bowl.
Remove the crackers and allow the crackers to rest about 5 minutes. Stir them around on the baking sheet and coat them in the cinnamon and sugar mixture, tossing everything around halfway through for an even coating of cinnamon flavor.
Let the crackers continue to fully cool and harden slightly before placing them into a bowl for serving. Stir in the M&M's or chocolate chips and enjoy!