01 - Preheat oven to 350°F. Line a 10x15 inch baking sheet with aluminum foil and coat with non-stick cooking spray.
02 - Lay saltine crackers in a single even layer across the bottom of the prepared baking sheet, covering the entire surface.
03 - In a medium saucepan, melt the butter over medium heat. Stir in the brown sugar and salt, then bring to a boil. Continue stirring and let the mixture bubble for 3 minutes. Remove from heat and stir in the vanilla extract.
04 - Immediately pour the hot toffee mixture over the saltine layer, spreading it evenly with a spatula to coat all crackers.
05 - Bake for 7 to 8 minutes, or until the toffee layer is bubbling across the entire surface.
06 - Remove the pan from the oven and immediately scatter the white chocolate chips in an even layer over the hot toffee. Let sit for 2 minutes to soften, then gently spread the melted chocolate into a smooth, even layer.
07 - In a small bowl, combine the granulated sugar and ground cinnamon. Sprinkle the cinnamon sugar mixture evenly over the warm white chocolate layer.
08 - Allow the toffee to cool completely at room temperature for about 40 minutes, or refrigerate to speed up setting. Once fully set, break into 24 pieces by hand or cut with a sharp knife.