Special equipment: 2 (10-ounce) ramekins
For the apples and cranberries: Combine the water, sugar, cinnamon, cranberries, and salt in a small saucepan and bring to a boil over high heat. Cook until the sugar is completely dissolved, about 1 minute.
Add the apples, reduce the heat to medium and cook, stirring occasionally, until the apples are soft but still retain some of their shape and the mixture has thickened, about 10 minutes. Set aside while you make the oatmeal.
For the oatmeal: Preheat the broiler. Put the milk in a medium saucepan and bring to a boil over high heat. Stir in the oatmeal, orange zest, and salt and cook until the mixture thickens, about 2 minutes. Cover and let sit for 2 minutes. The oatmeal should be slightly loose, it will continue to thicken under the broiler.
Divide half of the apple mixture between 2 10-ounce ramekins. Divide half of the oatmeal between the 2 ramekins and spoon on top of the apple mixture. Place the remaining apple mixture on top of the oatmeal then top the apple mixture with the remaining oatmeal. Smooth out the top of the oatmeal and sprinkle 1 tablespoon of the sugar evenly over the top of each.
Place the ramekins on a baking sheet and place until the broiler. Broil until the sugar is golden brown and bubbly and completely melted, about 2 minutes. Remove from the oven and let rest a few minutes before serving.
Apple mixture can be made 2 days in advance and stored in the refrigerator in a container with a tight fitting lid. Bring the mixture to room temperature or reheat over low heat on top of the stove or in a microwave for a minute before using.