Buttery Lemon Layer Cake with Swiss Meringue Buttercream
Somebody help me: After 35 years, I think I’m developing a sweet tooth.
Tragic, right? Get over it and join the rest of the world, Mouse.
All my life, I’ve always been a salty snacker. I’d happily chomp on cheese over chocolate, pizza over pastry, meat over munchkins. You get the picture.
But this cake, I ate 2 big slices the first night I made it.
I’m not sure where the chink in my armor was, but I have a feeling that it was the ice cream that did it to me.
Spending months completely immersed in sugar, honey, heavy cream, and chocolate changed my snacking DNA. It must have.
I’ll hand it to Martha Stewart. Love her or hate her, the lady can bake.
This recipe is adapted from her Baking Handbook. If you don’t have it, you should. It’s an indispensable reference for bakers of all levels.
I don’t know about you, but we’re ready for warmer weather here in Salem.
The daffodils are starting to show their sunny little faces in the yard. The squirrels are running around like crazy, chattering in the big pear tree out back. (And it’s only early March…)
This cake is just perfect for spring. Four layers of delicate cake that are packed with fresh lemon flavor and coated in clouds of swiss meringue buttercream.
If a cake could fly, this one just might.
Lemon curd filling!
So, I filled this cake with luscious lemon curd. You can buy it in a jar, or make your own (stay tuned for a post soon on how to do this, it’s really simple).
One word of caution if you use lemon curd off the shelf: If you’ve never had the brand, taste it the day before you’re going to use it, so you have time to replace it if it’s awful. Some brands are excellent (Stonewall Kitchen) and some are really fake and sugary.
If lemon curd is too fussy for you, you can always opt for whipped cream spiked with fresh lemon zest and a tablespoon of Limoncello.
Serve fat slices after Easter dinner or a lazy Sunday brunch. Or (I’m more inclined to this one), bust the cake out as the centerpiece for a late-night, backyard cocktail party. It would be an amazing with a frosty lemon drop, citron martini, or tall pitcher of homemade lemonade.
Garnish with some fresh mint leaves, a little lemon zest, and a scoop or two of lemon gelato.
Terrified of cooked frosting?
Don’t be. I’ll show you how to make a swiss meringue buttercream that’s so good you’ll want to eat it by the bowlful.
I used to be terrified of cooked frostings:
They’re so complicated! I know I’ll screw it up! Whatever, I’ll just frost it with whipped cream…
If you’ve ever been frosting-phobic, you know what I mean.
Honestly, though? They’re really not that bad. They’re totally delicious, look glossy and grand, and sound super fancy to boot.
A word on timing
Plan ahead. Seriously.
The cake needs to cool completely (as in, completely completely) before you frost it. If you try to rush it and frost a warm cake, the heat from the cake will melt your frosting and you’ll wind up with a runny mess. Trust me.
Alrighty. Let’s bake a cake, shall we?
Buttery Lemon Layer Cake with Swiss Meringue Buttercream
Lemon Butter Cake
1 3/4 cups sugar
16 Tablespoons butter (that’s 2 sticks), at room temperature
4 large eggs
1 Tablespoon Limoncello or other lemon liqueur
1 1/4 cups whole milk
3 cups cake flour
1 Tablespoon baking powder
1/2 teaspoon salt
Zest from 3 large lemons
3 – 4 cups lemon curd, for filling
Makes two 9-inch round cakes
Swiss Meringue Buttercream
4 large egg whites
1 1/4 cups sugar
24 Tablespoons butter
1 teaspoon Limoncello
Zest from 1 large lemon
Makes enough to frost two 9-inch cakes
Prep your pans & pre-heat the oven
Pre-heat your oven to 350 degrees.
Grab your cake pans. Cut two loose circles of parchment paper to fit inside each. (Skip the protractor…they don’t have to be super exact.)
Make the lemon cake batter
Cut the butter into chunks. Put the butter and sugar in the bowl of your mixer.
Beat briskly to cream the butter and sugar together.
You want it to look about like this (kind of like good mashed potatoes).
Add the eggs.
Beat until light and fluffy.
Toss in the milk and beat to incorporate.
In a separate bowl, combine the cake flour, baking powder, and salt. Whisk together gently until uniform.
Why cake flour?
Cake flour has less protein than regular, all-purpose flour.
Well…protein in flour helps develop gluten. Gluten makes stuff chewy. Which is great for a loaf of crusty French bread, but not so desirable for a delicate cake.
So, using cake flour will produce a more tender cake. Most grocery stores will have it in the baking aisle.
Add the flour/baking powder/salt mixture to the butter/sugar/egg mixture and beat to until just combined.
Add the lemon zest and beat quickly to incorporate.
Divide the cake batter between the two prepared pans.
Smooth down the surface of each cake.
Bake the lemon cakes
Pop them into your pre-heated, 350-degree oven and bake for 30-35 minutes.
They’re done when they’re golden brown on top and the edges, and a toothpick comes out clean. (Click here for how to test a cake with a toothpick.)
Let them cool on a rack on the counter for about 20 minutes, then run a knife around the edge to loosen them.
Remove the cakes from the pans. (Spread one palm out on top of the cake, then quickly invert the cake pan with the other hand. The cake should flip right out.) Peel off the parchment paper and discard.
Let the cakes cool completely on a wire rack.
(Again, seriously let them cool all the way. Warm cake + frosting = a sad, runny mess.)
Assemble the lemon layer cake
Now, I’m not good (like, not good at all) at transferring whole cakes once they’re frosted. If you are, more power to you. If you’re not, set one of the cakes on the platter you’re going to serve it on. (In this case, my cake was traveling, hence the disposable platter.)
To Trim or Not to Trim?
Depending on how slanted the sides of your cake are, you might want to trim them so that they’re more vertical.
If they’re really domed on top, you may want to trim the top off to make a more level surface.
Mine weren’t bad, and I’m always OK filling in any gaps with frosting and not stressing over cake shape.
Bottom line? Don’t stress and do what feels right to you. After all, it’s just a cake. It’s not supposed to freak you out.
With a serrated knife, slice your bottom cake in half horizontally. You want to aim for two relatively even layers.
Set the top layer aside for a minute while you fill the bottom layer.
Spread about half the lemon curd on the bottom layer. I like to spread the filling just a little shy of the edge. When you put a layer of cake on top of the filling, it’s naturally going to squish out a little.
(Hello, sunshine, right?)
Set the top half of the cake on top of the lemon curd.
Repeat with the second cake and the remaining half of the lemon curd.
Set aside while you make the frosting.
Make the swiss meringue buttercream
We’re going to improvise a double boiler.
If you have one, use that. If not, all you need is a medium-sized pot and a heatproof bowl that can nest inside of it.
The bowl should be big enough that it rests steadily on the edges of the pot without touching the bottom (see picture below). For example, I use a 3-quart pot and the stainless bowl from my Kitchen-Aid mixer. It fits perfectly and the high sides on the bowl help minimize splatter as I whisk.
Put about an inch of water in the bottom of the pot. Set it on the stove over high heat. Bring it to a boil. When it’s boiling, knock the heat down a little so the water holds a simmer.
Put the sugar and egg whites in your heatproof bowl.
Whisk well to combine.
Set the bowl over your pot of simmering water.
Whisk constantly until the mixture has thickened and it reaches 160 degrees on a candy thermometer.
(Eggs are cooked at 160 degrees, so your frosting will be cootie-free.)
When the mixture reaches 160 degrees, remove it from the heat. Beat it with an electric mixer for about 6 minutes, until it reaches stiff peaks.
As you beat, the egg whites will poof up considerably.
When the mixture reaches stiff peaks, add in the butter chunk by chunk, with the mixer running. (If you’re using a stand mixer, switch to the paddle attachment here. If you have a handheld, don’t sweat it.)
Beat in all the butter, then continue to beat for 3-5 more minutes, until the frosting is thick and glossy.
Finally, beat in the vanilla and lemon zest.
Frost your lemon layer cake
PHEW! Are you excited? I am. You’re moments away from a layer cake that would make Nana proud.
Start by putting a super thin layer of frosting over the entire cake. This is called a crumb layer, and is just what it sounds like: It catches all the little loose crumbs on your cake so that the final frosting is crumb-free.
Then put the rest of the frosting on the cake, and spread it around with a spatula. I tend to get very practical about cake frosting. You can use all sorts of specialized implements and techniques. I usually use a regular ole rubber spatula.
And, voila! One 4-layer lemon cake filled with lemon curd and draped in swiss meringue frosting. Enjoy!