1Reserved 1c. cake mix, set aside. Mix remaining cake mix with 1T. oil & 1 egg, mixture will be crumbly. Spray a 13x9 in pan with pam, press mixture in the bottom & up sides of pan. Take remaining cake mix & mix with the softened cream cheese & sugar, scraping the bowl while mixing. Add the remaining 3 eggs & vanilla, mix well. Add the milk & mix until all is mixed together. Pour into the 13x9 in pan & bake at 300 for 1 hr. All oven are different, so might take more than an hr. Shake the pan, if it stays firm it's done. Enjoy with cool whip or ice cream.