Butter baking dish and dust with cinnamon2. Whisk together eggs, milk, sugar, and pumpkin spice seasoning in large bowl3. Tear buns into small pieces in baking dish and pour the egg mixture on top4. Put flour, brown sugar, cinnamon, salt, and half stick of butter in bowl2. Sprinkle streusel on top of French toast bake and bake for 40 minutes3.