While sweet potatoes bake, quarter and core apples without peeling. Cut each quarter into about 16 pieces, making 3 slices lengthwise and 3 across. Leaving the peel on helps the apple pieces hold their shapes, adds nutrition, and saves you time. Put apples in the greased baking dish, sprinkle with cinnamon, nutmeg, and salt, and then toss to coat apples with spices. Spread into an even layer, add water, cover with foil, and bake on the bottom shelf for 30 minutes (22 minutes if using convection).