Preheat oven to 375 degrees. Place pecan halves in small roasting pan in single layer and bake for about 4 minutes, until they’re just toasted. Remove from oven and place in bowl, allowing to cool.
Chop pecans into small pieces. Place brown sugar in small bowl and break up with fork . Mix with pecans, currants, lemon zest, cinnamon, and nutmeg. Set aside.
Core each apple with a small knife, being careful not to pierce through the bottom of the fruit. If necessary, use a spoon to scoop out seeds and tougher core flesh from bottom. Widen the hole in each apple a bit. Peel the top half of the apple.
Stuff the hollowed core with the pecan-brown sugar mixture. Dot each filling with 1 teaspoon of butter, broken into small pieces. Sprinkle 1 1/2 teaspoons of coconut sugar around the top of each apple. Place in a small baking pan and pour applejack into the bottom.
Place on middle shelf in oven and bake for about 50 minutes, basting every 15 minutes or so with pan juices.
Remove from oven and allow to cool a bit. Serve as is or with vanilla ice cream, drizzling some of the pan juices over.