Cinnamon and Apple Crisp

1 cup firmly packed golden brown sugar
1 tablespoon ground cinnamon
3 1/2 pounds Granny Smith apples, peeled, cored, sliced (I used unpeeled Gala)
1 cup all purpose flour
1 cup sugar
1 cup (2 sticks) chilled unsalted butter, cut into pieces

Preheat oven to 450°F. Butter 13x9x2-inch glass baking dish. Combine brown sugar and cinnamon in large bowl. Add apples and toss to coat. Transfer apple mixture to prepared dish.

Combine flour, 1 cup sugar and butter in medium bowl. Using pastry blender or fingertips, blend ingredients until coarse meal forms. Spread flour mixture evenly over apples.

Bake crisp 20 minutes. Reduce oven temperature to 350°F. Bake crisp until apples are tender and topping is golden brown, about 30 minutes. Let stand 15 minutes before serving.