Preheat the oven to 375 degrees Fahrenheit.

Cut the tops off the apples, the core out some of the flesh from the inside. You can use a spoon, melon baller or a cookie scooper. Just be careful not to break the skin of the apples. Keep enough of the apple flesh, you just want to take out enough to add the crisp topping inside.

In a mixing bowl combine the flour, brown sugar, pumpkin pie spice, pecans, vanilla, and oats. Add the butter, and use your fingers to mix the butter into the mixture pressing it firmly into it.

Add the filing evenly to the apples. Put the apples into a baking dish with about one inch of water on the bottom. The water will help create steam to soften the apples while baking.