Preheat over to 350 degrees.
Mix together the sugars, flour, nutmeg, oil and salt.
Once combined remove 1 cup of this mixture and set aside (topping).
In a separate container mix together the buttermilk, egg, baking powder and baking soda.
Add the buttermilk mixture to the flour/sugar mixture and mix until combined.
Pour this mixture into a baking dish. I used an 8"x 10".
Sprinkle the 1 cup mixture you had set aside on top for the crumble.
Bake for 30-35 minutes.