1. Preheat your oven to 400°F (200°C) and line a large baking sheet with parchment paper.
2. In a large bowl, toss the cubed sweet potatoes with olive oil, maple syrup, cinnamon, nutmeg, salt, and cayenne pepper if using. Make sure every piece is well-coated.
3. Spread the sweet potatoes evenly on the prepared baking sheet, ensuring they are in a single layer to promote even roasting.
4. Roast in the oven for 25 minutes, stirring halfway through to ensure they cook uniformly.
5. Add the walnuts to the baking sheet and continue roasting for 10-15 more minutes, until the sweet potatoes are tender and caramelized, and the walnuts are fragrant and golden.
6. Once done, remove from the oven and let them cool slightly before serving. If you’re feeling fancy, garnish with fresh rosemary for a pop of color.

Remember, the real magic happens with that first bite—it’s sweet, crunchy, and just a little spicy. I like to add a dash of cayenne to give it that unexpected twist, a little nod to those lively dinners of my childhood.