Preheat oven to 350 degrees.

Place apples in a 9x9 baking dish. Sprinkle apples with the 1 1/2 tsp cinnamon and brown sugar. In a bowl mix melted butter, flour, sugar, oats, and 1 Tbls cinnamon to form a crumbly mixture. Sprinkle mixture over apples. Dot with remaining butter.

Bake 50 minutes until lightly browned and apples are tender.