Depends on sweet potatoe, doesn't it?

Some are small and some are large, and some have a very irregular shape. In general, they are baked just as regular potatoes are, although you want to be sure to snip off one end or pierce the sweet potatoes about halfway through baking to keep them from bursting. We roast them on a sheet pan (you can put them on a rack on a pan with sides) because of their tendency to leak their sugary juice all over our clean oven.

We actually cook them at a higher temperature – 400 °F (205°C) in a conventional oven; 375°F (190°C) in a convection oven. They are done when you can stab them through the thickest part with a knife and the center is soft, generally 40 minutes to an hour. If you roast them at a lower temperature, it will just take longer.

We also spell them the same way we spell regular potatoes – without an e in the singular.