The best type of apple to buy for these (at least in my opinion) is Cortland. If you can't find Cortland apples, just be sure to buy a variety that holds its shape when cooked, otherwise you will just end up with a big mush of apple.
We had these twice while our visitors were here. The first time, I did it according to the recipe and cored the apples and stuffed them with the filling (omitting the pecans, since Ash is allergic). The second time, I had Chloé in my arms while preparing them, so I opted to cut the apples into chunks instead and just dump the topping over them. Not a good idea... it was edible, but not as tasty. The oatmeal doesn't get soft from being inside the apple the way it does if you core them. I also suggest putting the apples individually in oven-proof bowls, if you have them, instead of cooking them on a baking sheet, as it will contain the mess of each apple as it cooks.
1/2 C oatmeal
2 tbsp. raisins
1 tbsp. pecans
4 tsp. brown sugar
4 tsp. maple syrup
1. Preheat the oven to 350oF. Empty the centre of the apples.
2. Combine the oatmeal, raisins and pecans, then put 1/4 of the mixture into the cavity of each apple.
3. Sprinkle apples with brown sugar, then pour the maple syrup over top. Cook for 40-45 minutes.
Makes 4 servings.
In passing, I had posted in my maple surprise post last week that I was going to try the recipe again with only 1/4 C of maple syrup. Not recommended. I think 1/2 C is the minimum you can get it down to and have it still be really yummy. I ended up adding an additional 1/4 C after it was all cooked, but it still didn't taste quite the same as when I had added the full 1/2 C in the beginning of cooking. So I'd recommend at least 1/2 C - or more, if you like things very, very sweet.