01 - Preheat oven to 350°F. Line a rimmed baking sheet (9x13 inches) with parchment paper or aluminum foil and lightly grease the surface.
02 - Lay the saltine crackers in a single even layer across the entire baking sheet, covering it completely with no gaps.
03 - In a medium saucepan, melt the butter over medium heat. Stir in the brown sugar, cinnamon, and salt. Bring to a boil and cook for 3 minutes, stirring frequently, until the mixture thickens and becomes bubbly.
04 - Carefully pour the hot toffee mixture evenly over the arranged crackers. Use a spatula to spread it into a uniform layer, ensuring every cracker is coated.
05 - Bake for 8 to 10 minutes, or until the toffee is bubbling across the surface and has turned a deep golden brown color. Remove from the oven.
06 - Immediately scatter the white chocolate chips or chopped chocolate over the hot toffee surface. Allow to rest for 2 minutes so the residual heat softens the chocolate, then spread it into an even layer using a spatula.
07 - In a small bowl, combine the granulated sugar and ground cinnamon. Sprinkle the mixture evenly over the melted white chocolate layer.
08 - Let the toffee cool completely at room temperature, then transfer to the refrigerator and chill for about 30 minutes until fully set and firm.
09 - Once fully set, break the toffee into irregular pieces by hand or cut into neat squares with a sharp knife. Serve immediately or store in an airtight container.