Preheat* the oven to 200°C (400°F) and use parchment paper to line a baking sheet with higher edges.
Place the sweet potatoes cut-side down onto the baking sheet. Bake for 25-30 minutes, depending on size, or until a fork can easily pierce through the thickest part.
2 medium sweet potatoes
Serve immediately or cool before storing in the refrigerator for 3-5 days.
Notes
* You can put the sweet potatoes in the oven without preheating, as the temperature doesn't need to be completely steady. They'll take about the same amount of time, maybe a couple minutes longer to make up for that preheating time.