Preheat the oven to 400°F and line a 10×15-inch baking tray with parchment paper. Arrange the saltine crackers in a single, contiguous layer on the prepared sheet. In a medium saucepan over medium-high heat, combine the butter and brown sugar, whisking continuously until the mixture reaches a gentle boil. Maintain the boil for a few minutes, then immediately pour the hot toffee mixture over the arranged crackers, spreading it evenly. Transfer the tray to the oven and bake for 4 minutes. As the toffee bakes, mix the granulated sugar and cinnamon in a small bowl and reserve. Remove the pan from the oven and promptly scatter the white chocolate chips over the hot toffee-coated crackers. Let the chips sit for a moment to soften, then spread the melted chocolate evenly with an offset spatula or knife. Sprinkle the cinnamon-sugar mixture uniformly over the melted chocolate. Allow the dessert to set and harden fully—placing it in the refrigerator can expedite this process. Once firm, cut into desired portions and serve.