Preheat your oven to 350 degrees F (175 degrees C). Line an extra-large rimmed baking sheet with aluminum foil and cover it with parchment paper.

Spread the oyster crackers evenly in a single layer on the prepared baking sheet.

In a small bowl, combine 1 teaspoon of ground cinnamon, granulated sugar, and kosher salt. Set aside.

In a small saucepan over medium heat, melt the butter and stir in the brown sugar. Bring to a boil and boil for 2 minutes, stirring occasionally. Remove from heat and stir in vanilla extract and remaining 1 teaspoon of ground cinnamon.

Pour the hot toffee mixture over the oyster crackers. Gently toss or stir to coat evenly.

Bake in the preheated oven for 10 minutes or until bubbly and golden.

Remove from the oven and sprinkle the reserved cinnamon sugar mixture over the warm crackers.

Allow to cool completely on the baking sheet. Break apart any large clusters. Serve.