There are a lot of theories to frosting a cake. I tried them all. I needed every trick a baker has to make my frosting skills look pro. And I got close -- sort of.
My happy couple decided on a chocolate cake after one bite of Rose Levy Beranbaum's Deep Chocolate Passion cake. Lucky for me, the cake is designed to be a wedding cake, but it's lacquered in chocolate ganache -- not a white buttercream. Not exactly what my bride had in mind for a wedding cake.
So I circled back to Rose, author of The Cake Bible and Rose's Heavenly Cakes, to figure out what type of buttercream would work for this cake without compromising the structure or taste. She recommended two options: a mousseline and her white chocolate-vanilla bean buttercream.
The latter recipe immediately perked my taste buds, but my baking skills were no match for this buttercream. The recipe calls for melting the butter and white chocolate together over a double-boiler. I did that, and then my emulsion broke because I let the water get too hot, and ended up with an oily mess. Luckily culinary school memories kicked in, and I immediately pulled this mixture from the stove and vigorously whisked it with a drop of cold water. I saved the buttercream, but at this point, I realized I should've taken baby steps. I'm going to make a mousseline, a buttercream that uses egg whites, for the wedding, which holds up well in room temperature and is suitable for piping decorations.
But to save money and time, I forged ahead with my salvaged white-chocolate buttercream because my main goal was to practice frosting a cake. Could I make buttercream look like fondant?
Two hours later, I realized something: It's not easy for a rookie to perfectly frost a cake. I had one of those kitchen moments where you want to run--screaming--from the kitchen because crumbs kept creeping into my just-smoothed sheet of frosting. Pair that with half of my frosting splattering on the floor, and I was about ready to call it "drinky winky" time as my grandfather used to say. But I took pages of notes on how to frost a cake--thinking I'd find one method that was the best. I ended up using every method to salvage my crumby job (pun intended).
I started with ¾ cup of frosting for the middle of my 8-inch layer cake. I let it slightly spill over the sides and then sandwiched the cake with the top layer. I did the same to the top of the cake. Then I started on the sides. I placed large globs of frosting on each side of the cake, working in small batches. The cake started to crumble too much, so I made a crumb coat: Basically a thin layer of frosting that catches any loose crumbs and seals them in. I kept two plastic containers handy--one to catch excess frosting, and one to catch frosting that was tainted with crumbs. I popped the cake in the fridge for 10 minutes to harden this layer.
For my next tactic, I piped the frosting along the sides of the cake to evenly distribute frosting to each side. This worked really well, but when I tried to smooth it with my metal spatula, it started to pull up the frosting rather than smooth it. Rose recommended dipping my off-set spatula in hot water and either shake off or wipe off the water. I found that a little residual water on the spatula made a smoother surface. Doing this is probably one of the most satisfying experiences a baker can have. It's like watching a Zamboni leave a trail of glistening ice behind. (Note: I've seen some people use a bench scraper instead of a spatula to smooth the sides.)
My last method of madness was to implement the paper-towel trick. I watched probably 10 YouTube videos on this technique, and it's pretty simple. Take a non-patterned paper towel (such as Viva), and place it on top of the cake once your frosting has set. Using your hands (or even better, a fondant smoother), run your hands over the cake smoothing out any bumps. Gently lift the paper towel. If you find it sticking, mist it with water, recommends Rose. Repeat this process on the sides of the cake, but a fondant smoother will be necessary. (I used the hot spatula technique for the sides of the cake.) I swiped any extra icing jutting from the top of the cake with a baby spatula. This is where a cake turntable comes in handy. Keeping you spatula steady with one hand, and rotating the cake with the other will make a smoother surface. I didn't have one, so I engineered my own:
It might look ridiculous, but it worked -- for now. The metal mixing bowl is friction-less and swiveled perfectly. And I plastic wrapped a cutting board so it wouldn't slide off the bowl. Lining the bottom of the board with non-slip shelf liners would work too.
When I started icing this cake, it looked awful. By the end, it came together. It's not perfect yet, but it's a major improvement. I have nine more months to nail this down.