You'll need:
3 cups mashed yams or sweet potatoes
3/4 cup milk
1/3 cup brown sugar
1/4 cup butter, softened
1 egg
1 teaspoon vanilla
1/2 teaspoon salt
Topping
1/3 cup brown sugar
3 tablespoons flour
1/4 cup grated coconut
1/3 cup pecans, chopped
3 tablespoons butter, melted
For yams (you'll need about 2 large or 3 medium yams), peel and dice into 1 to 2 inch pieces. Place in medium saucepan and fill with about 1 to 2 inches of water. (Water should come just to top of yams.) Bring to a boil, cover and steam on medium high for about 10 to 12 minutes (do not overcook.) Yams should be fork tender and easily mashable with a fork. Mash with fork. Measure out 3 cups and place in a medium mixing bowl. Add milk, brown sugar, butter, egg, vanilla and salt. Combine well. Place mixture in an 8" x 12" baking dish or casserole dish (a smaller baking dish is okay too.)
For topping, combine flour and brown sugar. Add coconut, pecans and butter. Mix well, until flour has absorbed butter. Sprinkle topping evenly over yam mixture.
Bake @ 350 degrees for 35 to 40 minutes.