Preheat the oven to 375 degrees F. Lightly spray an 8x10-inch baking dish with nonstick spray.
Spread the apples in the bottom of the baking dish. Sprinkle with lemon juice.
In a medium bowl, mix together the oats, brown sugar, flour, cinnamon, and salt. Pour in the melted butter and use a fork to combine. Use your fingers to sprinkle the crumb mixture over the apples.
Bake, uncovered, for 30 minutes- or until bubbly and hot.
Notes
*Great served warm with vanilla ice cream.
*Cover and refrigerate leftovers. Reheat leftovers to serve.