dried cranberries, powdered sugar, maple syrup, whipped cream, extra nuts, or other favorite French toast toppings
Grease the bottom and sides of a 9x13 baking dish with the melted butter (1 tablespoon).
Add the cubed bread to the baking dish and spread out evenly.
In a large mixing bowl, make the custard. Whisk together the eggs (6), half and half (2 cups), pumpkin puree (1 cup), brown sugar (1/2 cup), vanilla extract (1 tablespoon), and pumpkin pie spice (1 tablespoon).
Pour the custard evenly over the cubed bread in the baking dish. Cover and refrigerate for a minimum of 1 hour or a maximum of 24 hours (the longer it sits, the softer the texture will be).
In a small bowl, mix the streusel topping. Combine the chopped pecans (1/2 cup), all-purpose flour (1/4 cup), brown sugar (1/4 cup), and pumpkin pie spice (1 teaspoon). Add the cold, cut up butter (3 tablespoons) and use a fork, a pastry cutter, or your hands to blend the mixture together and break up the butter, forming a crumbly texture. (If making ahead, this can also be made ahead, covered, and refrigerated separately).
When you are ready to bake, preheat your oven to 350 degrees F and arrange a rack in the middle of the oven. Just before baking, sprinkle the streusel topping over the casserole evenly. Bake at 350 degrees F for 50-60 minutes, or until the casserole is no longer jiggly if you shake it a bit. If it's browning too much, you can tent it with foil.
Allow the casserole to cool for 5-10 minutes. Cut into 12 pieces (4x3). Top with dried cranberries, powdered sugar, maple syrup, extra nuts, whipped cream... or anything else you love serving French toast with!
Almost any bread can be used in this recipe, but the results will vary. I used brioche. Stale, slightly dry bread is recommended, but fresh bread can be used when cooking right away without an overnight refrigeration. Softer bread, like challah, brioche, and Texas toast, will absorb more custard and result in a softer texture (and may be a bit soggy if it's not dried out enough). Firmer, crusty bread, like sourdough or french bread, will hold their shape a bit more and the thick crust will result in a more firm and crunchy texture throughout. Sourdough has a tangy taste that balances well with the sweetness of the casserole, and challah and brioche are a bit sweeter to start with. If you choose a pre-sliced bread, opt for thick-cut.
To dry out fresh bread, you can leave it out overnight, in a paper bag or spread on a baking sheet covered with a towel (but not in a plastic bag or container, as those will keep the moisture in). For a faster method, you can cube or tear fresh bread and bake on a rimmed baking sheet in a 350 degree oven for about 15 minutes, until it's just starting to toast, but not brown. Let it cool and then proceed with the recipe.
Instead of half and half, you can use whole milk, or a mixture of whole milk and heavy cream. Ideally, use a milk with fat in it, but to lighten up the recipe or make it dairy free you can use low or non-fat milk or a plant-based milk alternative.
Almost any kind of nut can be used here. Chopped or sliced/slivered almonds would work well, hazelnuts, or a mix. Or, for a nut-free version, use pumpkin or sunflower seeds, or just leave them out!