Lemon butter frosting

We're spending this weekend helping a friend paint a few rooms in his new house. We just got the first coat up today, and will be spending tomorrow putting up the second coat. We baked a cake last night, and gave it to our friend today as a mini-housewarming gift; we frosted the cake with our favorite lemon butter frosting, and thus the frosting is this week's end-of-the-week recipe blogging post.

This frosting is extremely simple to make; it can be whipped up in less than 15 minutes, and only requires butter, powdered sugar, lemons, and a bit of salt. The finished frosting is very sweet, with a strong lemon flavor; it's a good compliment to many cakes, and we use it regularly on our lemon cakes. This frosting makes enough to coat a 9"x13" sheet cake generously.

1 teaspoon lemon zest
6 tablespoons butter
1/4 teaspoon salt
3 cups powdered sugar, sifted
1/4 cup lemon juice, freshly squeezed

1. Put the lemon zest, butter, and salt into a mixing bowl, and beat until smooth. We use our KitchenAid stand mixer for this, though you could also do it by hand if the butter were softened ahead of time.
2. Add approximately 1/4 of the powdered sugar to the butter, and beat until it is incorporated. Then add approximately 1/4 of the lemon juice, and beat until it is incorporated.
2. Continue alternately adding the powdered sugar and lemon juice until they are all mixed in. We find that using 1/4 cup lemon juice gives a good texture, but you can vary the amount of lemon juice to make a thicker or thinner frosting.
3. Frost your cake.

Frosting a cake is an art, but luckily the frosted cake doesn't have to look pretty to taste good. One trick is to apply a very thin coating of frosting (a "crumb coat") before putting the rest of the frosting on the cake; this crumb coat helps prevent the frosting from picking up little bits of the cake as you spread the final layer. I like to slide the edge of a serrated knife over the top of a frosted cake as a decorative touch.

We found a version of this recipe online many, many years ago, and have long since lost the original link.