Preheat your oven to 400°F (200°C). Wash, peel, and slice the medium sweet potatoes into thin, uniform rounds. A mandoline slicer works well for this, but a sharp knife will do the job. n a large mixing bowl, combine the olive oil, paprika, garlic powder, thyme, cinnamon, salt, and a dash of pepper. Mix well to create a seasoned oil.Place the sweet potato rounds in the bowl with the seasoned oil. Toss them by hand until all the slices are evenly coated with the oil and seasonings. Start creating stacks by layering the seasoned sweet potato rounds in a muffin tin or baking sheet. You can stack them vertically, slightly overlapping, to form neat stacks. Layer about 6-8 sweet potato rounds in each stack.
Place the sweet potato stacks in the oven and bake for 20 minutes. This will help them start to cook, become tender, and develop their crispy edges.
After the initial 20 minutes, remove the sweet potato stacks from the oven. Sprinkle each stack generously with shredded parmesan cheese and return them to the oven.
Bake for an additional 20 minutes or until the sweet potato stacks are tender on the inside and crispy at the edges, and the cheese is melted and golden.
Serve the crispy parmesan sweet potato stacks as a delicious side dish or appetizer. They're best enjoyed hot and fresh out of the oven.