Gather all of your ingredients.
Wash the sweet potatoes and cut the ends off.
Place foil on a cookie sheet and spray with cooking spray. Place the sweet potatoes/yams on the foiled and greased cookie sheet. The cooking time will depend on what size of sweet potatoes/yams you purchase. I used rather large sweet potatoes, it took 1-1/2 hours to bake them.
Remove the baked sweet potatoes/yams from the oven and allow to cool.
After the sweet potatoes/yams have had a chance to cool, it is time to peel and slice them to your desired thickness.
Next, throughly wash the apples. Using an apple peeler or other tool - peel, slice, and core the apples. Slice down the center of the peeled and cored apple to create apple slices that will be ready to be place in the casserole dish.
Grease a 9x13 inch pan and layer the sweet potato/yams and apples.
**It is time to make the sweet potato sauce! See below for instructions.**
Once the sauce has been poured over the sweet potatoes/yams and apples, it is time to bake.
Cover the sweet potato/yam mixture with foil and bake in the oven at (350°F) = (176°C) for 30 minutes. No marshmallows on this one. This recipe is fabulous! Enjoy!
It is time to prepare the sauce that will be pored over the layered sweet potatoes/yams and apples in the greased 9x13 in pan.
In a medium to large pot, combine the water, brown sugar, salt, and cornstarch, stirring constantly.
Add one cube (1/2 cup) of butter. Continue stirring constantly. Cook until it starts to thicken. Add 1/2 teaspoon of lemon juice.
Stir the brown sugar mixture constantly to keep from burning. Stir until the mixture is throughly mixed.
Pour the sweet potato sauce over the sweet potatoes/yams and apples. Try to make sure each piece is covered with the sauce.
Sprinkle with cinnamon and nutmeg (I forgot to add these earlier).