Preheat oven to 350. To make the streusel
topping, cut together in a medium bowl, 3 tbsp
brown sugar, 2 tbsp flour, nutmeg, cinnamon, and
chilled butter. You want this mixture to be
crumbly. Set aside.
In a larger bowl, combine remaining flour,
rolled oats, remaining brown sugar, baking
powder, baking soda, pumpkin seasoning, and
salt. Make a well in the center and set aside.
In a medium bowl, combine pumpkin, buttermilk,
oil, vanilla, and eggs.