Preheat oven to 375°.
To prepare streusel, lightly spoon flour into a dry measuring cup; level with a knife. Combine flour and next 6 ingredients (through allspice) in a bowl. Stir with a fork until mixture resembles coarse meal. Stir in pecans.
To prepare pears, using a melon baller or spoon, scoop out core from each pear half. Spoon streusel evenly into pear halves. Place pear halves, cut sides up, in an 8-inch square baking dish. Pour apple juice and apple brandy into dish. Cover dish with foil. Bake at 375° for 30 minutes. Uncover and bake an additional 5 minutes. Serve pears warm. Drizzle evenly with cooking liquid.