Prepare the bread. Cut the sourdough into approximately 1-inch cubes. Big, chunky pieces are what we're after. I use my homemade sourdough sandwich bread for this recipe. One loaf gives me about 4 1/2 cups of cubed bread, which is just right for this casserole. And if you don't have homemade sourdough hanging around, don't worry. A sturdy store-bought sourdough sandwich loaf will work, too.Spread them evenly in a 9x13-inch baking dish.

Add the cream cheese. If using, tuck the cubes of cream cheese randomly between the pieces of bread.

In a large mixing bowl, whisk together the pumpkin purée, brown sugar, pumpkin pie spice, eggs, whole milk, and vanilla until everything is smooth and well combined. Pour the mixture evenly over the cubed sourdough, making sure every piece gets some of that pumpkin goodness.

Assemble and refrigerate. Pour the pumpkin mixture evenly over the bread, making sure to coat as many pieces as possible. Cover tightly with foil and refrigerate for at least 4 hours, preferably overnight.

Preheat the oven. When you're ready to bake, preheat the oven to 350°F.

Make the streusel. In a medium bowl, combine the brown sugar, flour, and cinnamon. Cut in the cold butter with a pastry cutter or two forks until the mixture resembles coarse sand. Stir in the chopped pecans.

Add the topping. Remove the casserole from the refrigerator and sprinkle the streusel evenly over the bread.

Bake covered. Cover the casserole with foil and bake for 30 minutes.

Finish uncovered. Remove the foil and bake for another 20 minutes, or until the center is set and the topping is golden.

Rest and serve. Remove from the oven and let rest on a cooling rack for 5 minutes. Slice into portions, dust LIBERALLY with powdered sugar, and drizzle with pure maple syrup.