To prepare the apples, cut off the apple where it is its largest and cut off the bottom so the apple sits flat. Use a ring cutter small enough to leave about a quarter inch space around the edge of the apple when it is placed on top. Push the cutter into the apple and hollow it out being careful not to remove too much from the base of the apple causing it to leak when filled with liquid.
To prepare the base, in a sauce pan, bring the cream, milk and vanilla beans to a simmer. In a bowl, mix the sugar and yolks together. When the liquid comes to a boil, pour over yolks and combine constantly whisking. Strain into a container.
Get steamer ready on medium-low heat. Place apples in the steamer and fill with brûlée base and cover. Check the brûlées in about 10 minutes. If they are done they will have slightly risen and almost set. Cooking times may vary and when done remove from steamer and let cool at room temperature and then chill.
They can be served at either room temperature or out of the fridge. Dust with granulated sugar and burn using a pastry torch.