Preheat the oven to 350°F with a rack in the middle. Butter a 9-x-13-inch baking pan or 12-inch Dutch oven.
In a medium bowl, combine the flour, sugar, and brown sugar. Cut in the butter with a fork until crumbly.
Place the apples in the pan. Sprinkle the Jell-O packet evenly over the apples, then sprinkle with the crumble mixture.
Bake for about 40 minutes, or until bubbling slightly around the edges and the crumble begins to brown. Serve warm alone or as a warm topping over vanilla ice cream.