Spanish Cake

2 ½ cups flour
1 cup brown sugar
¾ cup white sugar
2 teaspoons cinnamon
½ teaspoon salt
¾ cup vegetable oil
1 teaspoon baking powder
1 teaspoon baking soda
1 beaten egg
1 cup buttermilk

Mix flour, brown sugar, white sugar, cinnamon, salt, and oil together until well blended.  Set aside 1/3 of mixture for topping.  Add baking powder, baking soda, beaten egg, and buttermilk to remaining batter.  Pour into greased pan.  Pour reserved topping mixture on top.  Bake in 350 degree oven for 35 minutes, or until done