I love a well cooked sweet potato now and then. And if you cook it like this, adding butter is just gilding the lily. It's so sweet and creamy, you need nothing more than a fork. So this is I the best method I've found for making perfectly delicious sweet potatoes every time. It comes from Empowered Sustenance.
* Please note that the source recipe will instruct you to place aluminum foil on the bottom of your oven to catch the drippings. I've actually ruined the bottom panel in my oven doing that. So it's safest (and just as convenient) to use a cookie sheet on the rack below the potatoes.
INGREDIENTS
Sweet potatoes or yams
INSTRUCTIONS
1. Wash sweet potatoes, poke with a fork a few times and set directly on the oven rack in the middle of the oven - place a baking sheet on the rack just below to catch the drips
2. Set your oven to 425F and bake for 45 minutes for sweet potatoes that are 2-3 inches in diameter, an hour if they measure up to 4 inches in diameter, and an hour and 15 minutes for anything larger
3. When your timer goes off, let them rest in the oven for at least 30 minutes (up to an hour)
4. If you're not eating them that night, remove the skin and store in the fridge