0.8 cup butter unsalted softened cut into 1/2-inch cubes and
8 servings whipped cream
5 ounces walnuts cooled toasted finely chopped
Equipment
bowl
oven
baking pan
Directions
Put oven rack in middle position and preheat oven to 375°F. Butter a 12- by 9- by 2-inch glass or ceramic baking dish (3 to 3 1/2 quarts.
Stir together flour, oats, brown sugar, walnuts, cinnamon, and salt in a bowl, then blend in butter with your fingertips until mixture forms small clumps.
Peel and core apples and cut into 1/4-inch-thick wedges, then toss with lemon juice, granulated sugar, and flour in a large bowl.
Transfer to baking dish, spreading evenly.
Crumble oat topping evenly over apple mixture and bake until topping is golden and apples are tender, about 45 minutes. Cool slightly and serve warm.
Crisp can be baked 4 hours ahead and kept, covered, at room temperature. Reheat in a preheat 350°F oven until warm.