Cranberry-apple crisp with oatmeal streusel topping

Topping:
1 cup (packed) golden brown sugar
1 cup old-fashioned oats
3/4 cup all purpose flour
1/4 teaspoon salt
1/2 cup (1 stick) chilled unsalted butter, cut into pieces
Filling:
2 12-ounce packages cranberries
1 1/4 pounds Golden Delicious or Fuji apples (about 3 medium), peeled, cored, cut into 1/2-inch cubes
1 1/2 cups sugar
2 tablespoons apple juice or cider
Vanilla ice cream

1. For topping: Combine brown sugar, oats, flour, and salt in large bowl; toss to blend. Add butter and rub in with fingertips until mixture comes together in moist clumps. Cover; chill while preparing filling. (Topping can be prepared 1 day ahead; keep chilled.)
2. For filling: Preheat oven to 375 F. Generously butter 13x9x2-inch glass baking dish. Combine cranberries, apples, sugar, and apple juice in heavy large pot. Bring to boil over medium heat, stirring often. Boil until cranberries are tender and juices thicken slightly, about 5 minutes. Transfer filling to prepared dish. Sprinkle topping over.
3. Bake crisp until filling bubbles thickly and topping is crisp and deep golden brown, about 40 minutes. Let cool 10 minutes. Serve with ice cream.