Spray a 9X13 baking dish with non-stick baking spray and set aside.
In a large mixing bowl, combine the cake mix, oil, water, eggs and ½ teaspoon of the cinnamon.
When the cake batter is combined, pour into the baking dish and bake in the preheated oven for 30-35 minutes or until a toothpick inserted into the middle comes out clean.
Set cake aside to cool.
When the cake is cool, use a large straw or end of a wodden spoon to poke holes in the surface of the cake.
Prepare the filling by combining the sweetened condensed milk with the remaining 1 teaspoon cinnamon.
Stir to combine.
Pour the milk mixture all over the cake so it gets into all the holes you created.
Next spread the whipped topping all over the cake.
Top with the crushed Cinnamon Toast Crunch Cereal.
Refrigerate for 4 hours.
Serve and enjoy.
Notes
Store any leftovers in the refrigerator for up to 3 days.