Check your Krispy Kreme app to grab a FREE Kit Kat Doughnut today with any purchase! Limit one per customer. Choose any doughnut from the popular Kit Kat Collection – the Kit Kat Crunch Doughnut, Kit Kat Cookie Dream Doughnut, or the Kit Kat Salted Caramel Brownie Doughnut for free. $2.59 value. You must be a Krispy Kreme Reward member for this offer, but you can click here to sign up for free.