Preheat oven to 350 degrees.
Core apples, being careful not to cut through to bottom. Peel top 1/3 of apples and stand in baking pan.
Bring to a boil maple syrup, water, cinnamon, lemon juice and lemon peel. Pour mixture over apples and cover loosely with foil.
Bake 30 minutes. Remove from oven and add 1 tsp. butter to the core of each apple. Baste apples with pan juices, cover and bake 15 minutes, or until tender. Cool.
Cut 1 or 2 small holes in apples from outside to the core. Push worms halfway through the holes.