Lightly spray or butter a 9×13-inch baking dish or casserole dish and preheat the oven to 350 degrees.
Cut the loaf of bread into small cubes or rip into bite size pieces with your hands. Place the bread in the baking pan.
In a large bowl, whisk together the milk, pumpkin purée, eggs, sugar, pumpkin spice and vanilla extract.
Pour the pumpkin custard mixture over the bread and gently stir to make sure that the bread is evenly coated.
Next we’ll make the streusel topping. In a medium bowl stir together the flour, brown sugar, white sugar and pumpkin pie spice. Then add in the melted butter and stir until it is well incorporated.
Sprinkle and crumble the streusel topping all over top of the casserole. Cover the pan with tin foil and bake the French toast casserole in the oven for 40 minutes covered uncover the casserole then bake for an additional 15 minutes or until the top is golden brown.
Remove the French toast bake from the oven and allow to cool for 10-15 minutes and serve while still warm.