In a medium mixing bowl, whisk together eggs, milk, pumpkin puree, 2 Tablespoons melted butter, molasses and 1 teaspoon pumpkin spice blend.
Dip each slice of bread into the mixture to coat well, then place, one layer thick, on a 13x17 baking sheet. Drizzle any remaining pumpkin mixture on top of the bread.
Place plastic wrap over the soaking bread slices and refrigerate for 8 hours or overnight.
In the morning...
Preheat the oven to 350°F. Generously butter an 8 x 11 baking dish. Mix together brown sugar with remaining teaspoon of spice blend.
Remove plastic wrap from the soaked bread and brush tops lightly with remaining 2 Tablespoons of melted butter. Sprinkle French toast tops all over with cinnamon sugar mixture.
Starting with the smaller pieces, arrange the slices of bread in the buttered baking dish, propping them up on top of each other until the pan is full. Place on the middle shelf of the oven and bake for 35-40 minutes until the tops are crispy.