Stir dry ingredients, including spices, together. Set aside.
Mix pumpkin, milk, butter or oil, and vanilla together until smooth. Pour over dry ingredients and fold together with a spatula, into a thick batter.
Spread into an 8" square deep casserole pan.
Mix the sugars and half the pecans. Sprinkle on top of the cake batter.
Pour hot water over the top, without stirring. and bake at 350° for 25 to 30 minutes. Place on a cookie sheet in case it runs over. Add the rest of the pecans and bake another 15 minutes.
Serve hot with vanilla ice cream.