Mix together oil, eggs, sugar and pumpkin in a large bowl or a stand mixer with paddle attachment.
Add in flour, baking powder, baking soda, salt and spices. Stir until combined.
Pour into a greased 10 x 15 inch sheet pan
Bake at 350 degrees F for 25-30 minutes or until a toothpick comes out clean.
Cream Cheese Frosting
Mix together softened cream cheese, vanilla, butter, milk, powdered sugar and beat with an electric hand mixer until smooth. Can also use a stand mixer.
Frost cooled cake with mixture and sprinkle with nuts if desired.
Notes
Don't over mix the batter. Mix just until ingredients are incorporated.
Dress up your pumpkin bars with chopped nuts such as candied pecans or walnuts, toffee bits or mini chocolate chips. You can also put the add ins into the cake batter too if you prefer. I use about 1 cup
Serve pumpkin bars without frosting if you prefer. Sprinkle with some powdered sugar or add some sweetened whipped cream and a drizzle of caramel sauce.