01 - Preheat oven to 350°F. Line a 10x15 inch baking sheet with aluminum foil and coat with non-stick cooking spray.
02 - Lay the 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 while stirring constantly. Let the mixture bubble for 3 minutes, then remove from heat and stir in the vanilla extract.
04 - Immediately pour the hot toffee mixture over the cracker layer, spreading it into an even coating with a spatula. Work quickly before it begins to set.
05 - Bake for 7 to 8 minutes until the toffee is bubbling across the entire surface. Remove from the oven carefully.
06 - Scatter the white chocolate chips evenly over the hot toffee surface. Let rest for 2 minutes until softened, then gently spread the melted chocolate into a smooth, even layer using a spatula.
07 - In a small bowl, combine the granulated sugar and ground cinnamon. Sprinkle the mixture evenly across the entire white chocolate surface.
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 with a sharp knife.