Preheat oven to 350°. Cut bread into 1-inch pieces. Spread pieces in a large, rimmed baking pan. Bake for 8 to 10 minutes or until slightly dry.

Lightly spray a 13x9-inch baking dish with nonstick spray. Spread dried bread cubes in prepared baking dish.

Whisk together eggs, sweetened condensed milk, pumpkin, ¾-cup brown sugar, pumpkin pie spice, salt, and vanilla extract in a medium bowl. Pour egg mixture evenly over bread pieces. Cover tightly with plastic wrap; refrigerate for 4 hours or overnight, or until egg mixture is absorbed.

Combine flour and remaining ¼-cup brown sugar. Cut in cold butter using a pastry blender or fork until pieces are pea-size. Cover and refrigerate for 15 minutes or overnight.

Preheat oven to 350°. Remove plastic wrap and cover baking dish with foil. Bake for 20 minutes. Remove foil and sprinkle with chilled brown sugar mixture. Bake, uncovered, for 30 to 35 minutes more or until a wooden toothpick inserted near center comes out clean. Let stand for 5 minutes. To serve, sprinkle with pecan halves. Top with whipped topping, if desired, and drizzle with maple syrup.