Preheat the oven to 425°F (220°C). Line a large baking sheet with parchment paper or lightly grease it.

Wash and dry the sweet potatoes. Trim the ends, then slice into 1/4-inch rounds for even cooking. Try to keep them the same thickness so they roast uniformly.

In a large bowl, toss the sweet potato slices with olive oil, sea salt, black pepper, smoked paprika, and garlic powder until each slice is lightly coated.

Arrange the slices in a single layer on the prepared baking sheet. Avoid overcrowding — use two sheets if needed so they crisp instead of steam.

Bake for 12–15 minutes, then flip each slice gently with a spatula and bake another 8–12 minutes, until edges are golden and centers are tender. Total time depends on thickness and your oven.

If you want extra crispiness, switch the oven to broil for the last 1–2 minutes, watching closely so they don’t burn.

Remove from the oven. Sprinkle with chopped parsley and grated Parmesan if using. Let cool for a minute or two — they firm up slightly as they rest.

Serve warm as a side, snack, or layer into sandwiches and salads.