Preheat oven to 350 degrees.
In a large bowl, combine apples, cranberries, and lemon juice, tossing to coat.
In a medium bowl, combine sugar, corn- starch, 1⁄ 2 teaspoon cinnamon, nutmeg, and salt. Add sugar mixture to apple mixture, tossing to coat. Arrange apple mixture in a 13x9-inch baking dish.
In a medium bowl, combine flour, oats, brown sugar, remaining tablespoon cinnamon, and melted butter, stirring until dry ingredients are moistened and mixture is crumbly. Sprinkle oat mixture evenly on top of fruit. Bake for 45 to 55 minutes or until lightly browned and crisp. Serve with ice cream, if desired.