Mix butter, sugar, pecans, oats and cinnamon together.
Stuff apple cavities with the filling. Place apples in an ovenproof, tight fitting dish. If you have any leftover filling, place the mixture on the bottom of the dish and sit apples on top.
Mix apple juice and maple syrup together and pour into dish.
Bake in preheated oven for 40-45 minutes. Baste every 10 minutes with the syrup and apple juice. The apples are ready when they are soft.