Preheat the oven to 350°F (176°C). Coat an 8-inch (20cm) square baking pan with nonstick spray; set aside.
In a bowl, whisk together the cream, pumpkin, milk, sugar, eggs, salt, and spices.
Toss the bread cubes with butter in another bowl and pour into the baking pan. Pour the pumpkin mixture evenly over the bread. Press the bread gently into the mixture, and allow it to sit for 15 minutes.
Bake until custard sets, 35 to 40 minutes. Cool before serving.
Notes
For added crunch, add your favorite chopped nuts. Walnuts work well with pumpkin.