Perfect Lemon Cake

I made this for Kevin's Birthday, it was so easy, yummy, and moist I had to share the recipe.
I got the cake recipe from a friend but I didn't like the frosting recipe that it came with so I improvised and came up with a new one. Yum!!

Cake:
1 package lemon cake mix
1 cup sour cream
3/4 cup water
3/4 cup oil
4 eggs
1 small package instant lemon pudding

Blend all wet ingredients together well. Mix dry ingredients and sift into wet mixture. Mix with electric mixer on medium speed for about two minutes.
Pour into a greased 9x11 pan or two round pans.
Bake at 350 degrees for 25 minutes or till a toothpick comes out clean.
Cool the cake completely - I always mess this up and think it's cool, but it never is. I have to refridgerate it for an hour- and then frost.

Fluffy Lemon Frosting
(by yours truly)
1 cup butter softened
1/2 cup lemon juice
1 tsp lemon zest (optional)
6 oz cream cheese softened
Beat until creamy
Add
Yellow food coloring to a shade darker than desired color (optional, the cake is yellow, so white lemon frosting is pretty too!)
Mix in 5 cups powdered sugar one cup at a time
1 1/2 cups Coolwhip (half a regular package)
the cool whip will lighten yellow color up again

Hints:
I find food color and Coolwhip don't blend together well if done at the same time.

You can use different consistancies of frosting, one for the middle frosting layer with 6 cups powdered sugar and and a lighter one for the outside of the cake (only 5 cups). I took out 1 cup of frosting after mixing 5 cups with the whole recipe, then I added 1 cup powdered sugar to that for a thicker middle frosting layer, this is so the cakes wouldn't slide apart.