Preheat the oven to 350 and butter an 8 cup pie plate or baking dish.
Melt the butter in a large skillet over medium heat. When the butter is browned and smells a little nutty add the apples. Saute until lightly browned.
Remove from the heat and add the Cavados, sugar, brown sugar, cinnamon, nutmeg and salt. Stir to combine. Set aside to rest for 30 minutes.
Make the Batter
Place the milk, sugar, eggs, vanilla, salt and flour in a blender. Cover and blend at high speed for about 30 seconds to one minute.
Make the Clafoutis
Pour the apples and their liquid into the buttered dish. Pour the batter over the apples. Place in the center of the oven and bake until it's puffed and browned and a knife inserted in the center comes out clean. About an hour to an hour and 15 minutes.
To serve dust with powdered sugar. Serve warm or at room temperature with a little ice cream if desired.