The Cinnamon Challenge

You target a creature within range, their mouth fills with cinnamon powder. Target must make a CON save equal to the casters spell save DC or spend their next turn coughing.
At the end of targets next turn they can reattmpt the save. If they fail, the target falls prone, coughing, and is incapacitated until the end of their next turn when they can attempt the save again. Every subsequent failure causes the DC to increase by 1. 

Spell lasts for 1 minute or until the target makes the save, whichever comes first.