Preheat oven to 350℉. Lightly grease 2 rimmed baking sheets or use a disposable roasting pan. Add the Bugles evenly among the pan(s) and set aside.
In a medium saucepan over medium heat, melt the butter and brown sugar. Bring to a boil and boil, stirring constantly, for 2 minutes. Remove from heat and whisk in the vanilla extract and one teaspoon of the ground cinnamon until combined.
Pour the hot toffee mixture evenly over the Bugles in the pan, immediately followed by HALF of the bag of toffee bits. Working quickly with a rubber spatula, toss the toffee mixture and the Bugles chips together so they get evenly coated.
Bake for 10 minutes. While they bake, stir together the remaining 2 tsp ground cinnamon and the granulated sugar in a small bowl. Set aside.
Remove the Bugles from the oven and immediately sprinkle with the remaining toffee bits and the cinnamon sugar, tossing to coat as you sprinkle. You really want to coat everything completely, so I like to liberally sprinkle, toss, and repeat until it is pretty saturated.
Let cool completely before breaking into pieces to serve.