Preheat oven to 350. Place cereal in a large, heat safe bowl. Line a large baking sheet with foil and spray with nonstick baking spray.
In a small bowl, combine cinnamon and sugar and set aside.
In a heavy saucepan over medium heat, heat brown sugar, butter, and corn syrup until the mixture comes to a boil. Let boil for one minute, stirring constantly, then remove from heat and stir in baking soda. Pour over cereal and stir until cereal is coated.
Spread cereal on prepared baking sheet. Sprinkle evenly with cinnamon/sugar mixture. Bake for about 5 minutes, then flip with a spatula and bake for 3 more minutes, until cereal turns golden brown. Remove from oven and let cool completely, then break up and store in an airtight container.