HI,
I'm not sure if you're using actual yams...which are hard to come by, or sweet potatoes...which are often mistakenly called yams, but I have something that worked out well and it was an accident. One evening I was going to bake the sweet potatoes as you seem to want to do. So I poked some holes in them with a knife and placed them unwrapped, but on a foil lined pan (they tend to ooze a little) in the oven at about 350-400 degrees F. They baked for about 30-35 min (they were average sized), then I had to leave the house for some reason so I turned the oven off and left them in there. Whatever I had to do took longer than expected and when I got home I'd forgotten about the potatoes. They remained in the oven overnight. Then next morning as I was getting breakfast ready I saw them. YIKES!!! I thought, but they were perfect for scooping out the insides. So that's what I did. I scooped out the insides and put them all in a bowl. Then I warmed them up in the microwave just until they were hot. Then I added some butter (the real stuff), cinnamon, and some white and brown sugar to the desired sweetness. YUMMMM! they were perfect. No leftovers!!
This may not be the way you want to go, but it worked out well because I didn't have to scoop potatoes out of hot skins.
I also have a wonderful country recipe (from South Central KY) for fried candied yams (sweet potatoes actually) that my grandmother has passed down to me if you're interested.