Scalloped Sweet Potatoes

1/2 teaspoon butter for baking dish
2 cups cold, boiled sweet potatoes in 1/4-inch slices, divided
2 cups thinly sliced tart apples, divided
1/2 cup brown sugar or less to taste
4 teaspoons butter, cut into small pieces
1 teaspoon salt, divided
2 tablespoons red cinnamon drops

Preheat the oven to 350°. Butter a 1 1/2-quart baking dish and set aside. Place half of the potato slices on the bottom of the baking dish. Cover with half the apple slices. Sprinkle 1/4 cup or less of the brown sugar, if desired, on top of the apples. Dot with 2 teaspoons of butter and 1/2 teaspoon salt. Repeat the layering with the remaining potato and apple slices, brown sugar, butter and salt. Sprinkle the top with the candies and bake for 1 hour. Remove from oven and serve.