Preheat oven to 350°F.
Combine butter and both sugars in bowl of stand mixer. Mix on speed 2 for 4 minutes.
Add eggs, one at a time, mixing until incorporated and scraping sides, if necessary.
Add vanilla, baking soda, salt, cinnamon, and flour, mixing until combined.
Take 2 cups of cereal and crush into small pieces.
Add to dough, stirring until combined.
Scoop heaping teaspoon of dough onto tray.
Flatten with hand.
Crush remaining cup of cereal into tiny pieces.
Sprinkle 1/2 teaspoon crushed cereal on each cookie. Press gently to adhere.
Bake for 12 minutes.