Yummy Yams

Directions

1. 1
   Boil sweet potatoes in a large pot of water until tender. Cool and refrigerate until cold.
2. 2
   Peel potatoes and slice lengthwise into 3 slices.
3. 3
   Line casserole dish (9 x 11-inch will work) with pats of butter, then layer with sweet potatoes, white sugar, brown sugar, cinnamon and butter.
4. 4
   Repeat the layers.
5. 5
   Add enough water to cover bottom of casserole dish (about 1/4 cup). Bake at 350°, uncovered, for 2 hours.
6. 6
   Top with marshmallows the last 5 minutes.
7. 7
   Watch closely to prevent marshmallows from burning.