Preheat your oven to 375 degrees Fahrenheit.
In a large bowl, mix the flour, brown sugar, sugar, cinnamon, and salt.
Add the butter to this mixture, cutting it in with a pastry blender or two forks until it forms coarse crumbs.
Arrange the sliced apples in a baking dish and sprinkle the crumb mixture evenly over the top.
Bake uncovered for about 40 to 45 minutes until the top is golden brown and the apples are tender.
Serve this warm and enjoy it with a scoop of ice cream or a dollop of whipped cream!