Preheat oven to 350 degrees F. Butter a medium size casserole dish.
Boil turnip in a medium saucepan until tender.
Drain and mash.
Add butter and egg and mix well.
Combine flour, brown sugar, baking powder, salt, pepper and nutmeg in a small bowl.
Mix into the turnip mixture.
Pour turnip mixture into buttered casserole dish.
Combine bread crumbs and melted butter. Spread evenly over turnip mixture.
Bake for 25 minutes or until light brown on top.