In a pot over medium heat, melt the butter and then mix in the brown sugar, stirring until everything is well combined.
Bring the mixture to a boil, then take it off the heat.
Stir in 2 teaspoons of cinnamon and 2 teaspoons of vanilla until fully incorporated.
Add the oyster crackers to the pot and toss them until they are completely coated with the sauce.
Spread the coated crackers in a single layer on a foil-lined sheet pan, flattening them into an even layer.
Bake in a preheated oven at 350°F for 15 minutes.
While the crackers are cooling, mix together 1 cup of granulated sugar, 2 teaspoons of cinnamon, and a pinch of salt to create the cinnamon-sugar coating.
Once the baked crackers are warm but not hot, drizzle or sprinkle the cinnamon-sugar mixture over them, tossing to ensure they are evenly coated.
Allow the coated crackers to cool completely before serving, or store them in an airtight container.
