Lemon Cake with Lemon Buttercream Frosting

I really like lemon desserts, but even people who don't (like my anti-lemon sister) seem to like this cake! Is it possible for a cake to taste refreshing? Because this one does!

Recipe adapted from here.

Ingredients:
{Cake}
1 package lemon cake mix (I use Duncan Hines)
1 cup sour cream
3/4 cup water
3/4 cup oil
4 eggs
1 small package lemon instant pudding mix

{Frosting}

1 cup (2 sticks) very soft butter (I just stick them in a bowl on the counter in the morning, then make the frosting later in the day after the butter's been warming for a good long while)

6-8 cups powdered sugar

1/2 cup lemon juice

1 tsp lemon zest

Directions:
1. Mix dry ingredients in the bowl of your electric mixer. Add wet ingredients. Mix on medium speed for a couple minutes (don't overmix!).
2. Pour into two round, lightly-greased cake pans.
3. Bake at 350 for 25-30 minutes (or until a toothpick inserted in the center comes out clean).
4. While cake is baking, make your frosting. Place the soft butter in a large mixing bowl. Add four cups of powdered sugar, the lemon juice, and the lemon zest. Beat until smooth.
5. Add remaining sugar one cup at a time until the frosting reaches a good spreading consistency (I always use all 8 cups to get a frosting that "crusts" a little after it's on the cake).
6. Cool cakes on wire racks. For best results, put each layer in the freezer for a couple hours before frosting.

(dry ingredients)

(mixing the batter)

(lemon cake batter!)

(into two cake pans...)

(frosting being mixed)

(post-frosting!)

(yumm!)

Ta-da!

Enjoy!