Okay, here are the steps to solve this:
* The recipe calls for 1 teaspoon of cinnamon for every 4 cups of granola mix.
* We are making 12 cups of granola.
* So to make 12 cups, we need 12 / 4 = 3 times as much cinnamon.
* Since each 4 cups uses 1 teaspoon, 12 cups will need 3 teaspoons.
Therefore, for 12 cups of granola mix, the recipe will call for 3 teaspoons of cinnamon.