Wash and peel the sweet potatoes. Slice the potatoes into ¼-inch-thick rounds.
Steam the sweet potatoes: Place a steamer rack in a large pot filled with 2 inches of water. Bring the water to a simmer, then add the sweet potatoes. Cover the pot and steam for 4 to 6 minutes, or until just tender but not falling apart. Remove the sweet potatoes and allow to cool.
Combine the spices in a small bowl, then sprinkle over the sweet potatoes.
Place the treats evenly between the COSORI Food Dehydrator trays.
Set temperature to135°F and time to 4 hours, then press Start/Stop.
Remove the treats when done and dried but still chewy on the inside. Cool to room temperature on the trays, then serve to your pet.