1. Preheat oven to 350°F. Spray a 12-inch cast-iron skillet with baking spray with flour.
2. In a large bowl, stir together bread and raisins. In another large bowl, whisk together cream, pumpkin, maple syrup, eggs, pumpkin pie spice, cinnamon, and vanilla. Pour over bread mixture; stir until combined. Let stand for 20 minutes.
3. Transfer bread mixture to prepared skillet. Bake until a wooden pick inserted in center comes out clean, 50 minutes - 1 hour, covering with foil halfway through to prevent excess browning, if necessary. Garnish with confectioners' sugar, whipped cream.