Preheat oven to 350F. Get out a 9x9 inch or similar sized casserole dish.
Mix together all the dry mix ingredients in a medium bowl.
For the wet mix, whisk together the milk, butter, vanilla, egg, and maple syrup in a large bowl. Mash the pumpkin with a fork so it's still a little chunky. Stir the mashed pumpkin into the wet mix.
In a small bowl rub together the streusel ingredients until everything is well mixed and the flour is coated with butter.
Add the dry mix to the wet mix. Stir to combine. Pour the oatmeal mixture into the casserole dish. Top with the streusel. Sprinkle some more dried cranberries over it if desired.
Bake the oatmeal for 30-35 minutes, or until most of the liquid is absorbed and the oatmeal is puffed and golden.
Serve topped with maple syrup and extra milk or yogurt if desired.