This is perfect for the fall weather and tastes so good. I think it tastes a little better the next day, as many cakes do. My son thought it was a carrot cake at first. This was supposed to be a brownie recipe, but the cake rises too much for me to call it a brownie. Still absolutely wonderful. I add more cinnamon than directed to the icing, but see what suits your taste. I'm sure you could sub a few teaspoons of pumpkin pie spice for the cinnamon and other spices and still have it taste fantastic.
Preheat oven to 350 degrees. Meanwhile, in a bowl mix together first eleven ingredients at medium speed until well blended--about two minutes.
Mix in by hand:
1 3/4 cup all purpose flour
just until blended in well with the wet ingredients. Don't use the mixer for this step, just stir.
Spray bottom of 9 X 13 pan with nonstick spray and pour in batter. Bake for 30 minutes.
When completely cooled, frost with cream cheese frosting (follow directions for icing in step 5):
Blend cream cheese and butter until smooth at low speed. Add vanilla. Slowly add powdered sugar a little at at a time until well blended. Add cinnamon. If it's too runny add a bit more powdered sugar until it's a good consistency. If too stiff, add a Tablespoon of milk or water and blend again.