Combine apple slices, cranberries, sugar, cinnamon, and lemon juice in a bowl.
Lightly butter a 1.5 quart baking dish (8x8-inch square pan). Add apple and cranberry mixture to dish.
In a separate bowl, blend softened butter with flour and brown sugar using a fork, until mixture is crumbly.
Sprinkle mixture evenly over the dish. Bake for 50-60 minutes, or until topping is golden brown. Allow to cool for a few minutes, and serve warm with vanilla ice cream.
Notes
If you want to make this dairy-free, just use a vegan butter substitute in place of the butter.I used Granny Smith apples for this recipe, but there are lots of other options you can use. See blog post for suggestions.