Place the chopped dried dates into a sieve and slowly pour 1 cup boiling water over to soften. Sit over a bowl to drain.
Use an apple corer to remove the core from the apples, plus a little extra flesh to make a 1½ cm wide hole. Use a small knife to cut around the belly of each apple, so they can open up while cooking and to prevent the skin from bursting.
In a mixing bowl, use a fork to mash together the softened dates and butter. Add the rolled oats and cinnamon and keep mixing until combined. Use your hands to press the mixture firmly into the apple cavities, mounding extra mix onto the top of each apple.
Place the apples into a small baking dish so they are sitting upright together, and add the water. Bake for 35-45 minutes until the flesh is soft. Note: the cooking time will vary depending on the variety of apple used and size.