01 - Preheat oven to 350°F and lightly grease a 9-inch square baking dish.
02 - In a large bowl, toss diced apples and cranberries with granulated sugar and flour until evenly coated.
03 - Spread the fruit mixture evenly across the bottom of the prepared baking dish.
04 - In a separate bowl, blend oats, flour, brown sugar, cinnamon, and salt; add diced cold butter and mix with a pastry cutter or fingers until crumbly.
05 - Evenly distribute the oat mixture over the fruit layer, gently pressing to compact.
06 - Bake in preheated oven for 40–45 minutes or until topping is golden and fruit is bubbling around edges.
07 - Allow to cool for 15 minutes before serving warm; optional: garnish with vanilla ice cream or whipped cream.