Lime Ombre Cake with Swiss Meringue Buttercream

Ah, the first of my cake posts. There are plenty of these to come! I've made a lot of cakes in my day (I like statements that make me sound wise beyond my years), but to be quite honest...I'm not a fan of cake. Is that allowed? Is it too soon to tell you that? Please still order my cakes, I swear there's still a good helping of love in them! I like the blank slate that a cake gives me to be creative with flavors, colors, and decorations. I think the frosting is where it gets me...it's just too sweet. So this particular cake was not sickeningly sweet, but by all means add more sugar/reduce the salt to your liking!

Lime Ombre Cake with Swiss Meringue Buttercream

Vanilla Cake recipe adapted from Rock Recipes
Lime Ombre Cake:

1 1/2 cups cake and pastry flour

1 1/4 cups all-purpose flour

2 1/2 tsp baking powder

1 tsp salt 
1 cup (2 sticks) softened butter
2 cups white sugar
4 room temperature eggs
2 tsp vanilla bean paste (or vanilla extract)
3/4 cup whole milk at room temperature
1/4 cup fresh lime juice
1/4 plain Greek yogurt
Food coloring of your choice

Preheat oven to 350 degrees F. Prepare 9" round cake pans with  butter, flour and parchment (you'll need 4 pans total, but I only have two--so I baked the first two layers, allowed them to cool a bit, removed them from the pans and re-greased them for the last two layers). Sift together flours, baking powder and salt. In a mixing bowl cream together butter and sugar. Add eggs one at a time, mixing well after each addition. Mix in vanilla. Alternate adding dry ingredients with wet ingredients (milk and lime juice) until just combined. Gently fold in yogurt. Divide batter into fourths. Add  enough food coloring to 1/4 of the batter to reach the darkest desired color. Add a little less food coloring to the next 1/4 (about half as much used for the darkest layer). Add even less to the next 1/4 of batter (very little food coloring at this point to reach a pale hue). No food coloring is necessary for the final layer. Bake each layer for 10-12 minutes, until toothpick inserted in the center comes out mostly clean, but not completely dry.

Adapted from Sweetapolita
Swiss Meringue Buttercream:
5 room temperature egg whites
1 cup + 2 tablespoons white sugar
4 sticks butter (I used salted, but would probably use unsalted next time)
1 1/2 tsp vanilla extract
1/2 tsp salt
Food coloring for decorating

Using a double boiler method, whisk egg whites and sugar in a bowl over a pot of simmering water until sugar is dissolved and egg whites are hot to the touch (or 140 degrees F if you feel like getting technical). Transfer egg white-sugar mixture to a mixing bowl fitted with a whisk attachment and whip until fluffy and cooled (this may take a little while!). Change to a  paddle attachment and beat in butter one tablespoon at a time. Mix in salt and vanilla. Finally, you can color some of the frosting for decorating, if you'd like!
Note: Many recipes call for one pound, or 4 sticks of butter for Swiss Meringue Buttercream, but I think I'd use less next time. It deflated the fluffy egg whites quite a bit, and a whole pound just didn't seem necessary. So I'll test it out and report back!

To assemble the cake start with the darkest layer on the bottom, moving up gradually with the lightest layer on top, laying buttercream in between. Then frost and decorate!

This method has been popping up quite a bit lately and takes very little extra effort, but makes quite the impact! Just don't try frosting a cake in 100 degree weather. Learn from my mistakes, my friends. I mean, we're still friends, right? Even after admitting my true feelings about cake? Ok, good, just checking.