Everyone knows that the classic birthday cake has to be a yellow birthday cake! I wanted to make this birthday cake recipe a bit ✨fancy✨, so you know I had to cover it in the creamiest, dreamiest chocolate Swiss meringue buttercream! This is the fancy version of your grocery store box mix, and your friends will think you bought this at the fanciest bakery in town.
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This yellow cake was one of my first recipes on the blog back in 2020! I actually made it after watching an absurd amount of Bon Appétit videos (it was the pandemic, I had a lot of free time) and seeing some of the gorgeous cakes they made.
I've now come back to it to rework the recipe and update the photos, because I have learnt a LOT in the past few years as a recipe developer. Believe me, this is way better than a box mix.
This easy vanilla birthday cake uses my tried-and-true vanilla cake recipe that you've probably seen in my berry vanilla cake and vanilla cake with strawberry frosting. It's extra moist and soft thanks to a combination of butter and oil. While using just butter is more traditional (and gives you tons of buttery flavor), swapping out some of the butter for a neutral oil will help keep the cake soft and moist.
What Even Is Swiss Meringue Buttercream?
I'm from Switzerland, so of course I'm using Swiss meringue buttercream! If you don't know what Swiss meringue buttercream is, it's a frosting that uses meringue as its base.
We cook up egg whites and sugar (I promise, it is so much easier than it sounds) over the stove, then whip it up in the stand mixer until you have a meringue. We'll then slowly add in cubed butter to make buttercream, and finish off with melted chocolate.
The reason why I love it is that it isn't overly sweet, it basically tastes like you're eating clouds, and because of the texture, it makes decorating a cake a breeze. I've used this recipe before in my chocolate cake with strawberry filling, and it was so fun to pipe that border edge with this buttercream.
Ingredients For Yellow Cake & Buttercream
- Neutral Oil = Super Soft Cake. After years (and years) of testing cakes and methods, let me tell you that adding in some neutral oil to your cake will always make it softer. Make sure you use a neutral oil like vegetable oil, canola oil, or sunflower oil. You want something that doesn't have a strong taste or smell.
- Get the Good Chocolate. I don't recommend using chocolate chips for the frosting. Chocolate chips usually have emulsifiers in them, so they don't melt when you're making chocolate chip cookies. Here, we want to melt the chocolate! Grab the good stuff if you can.
Let's Make This Birthday Cake!
- Combine butter with oil and sugar until light and fluffy.
- Add the eggs one at a time, stopping to scrape the bowl after each egg is added.
- In a separate bowl, whisk the dry ingredients together. Add to the cake batter in 3 additions, alternating with the buttermilk.
- Pour into two 8-inch greased and lined cake pans. Bake in a preheated oven at 350°F for 30-35 minutes.
- Fill a small saucepan with about an inch of water and place over low heat on the stove. In a heat-proof bowl, whisk the egg whites and sugar over the double boiler. Whisk until the sugar has dissolved, or it gets to 140°Fahrenheit.
- Take the bowl off of the saucepan. Place in your stand mixer with the whisk attachment. Whisk until you have stiff peaks on medium-high speed. This can take some time, sometimes up to 20 minutes for me.
👩🏻🍳 From My Test Kitchen: If you don't have a thermometer to check the temperature of the sugar and egg whites, then here's a trick I do: lift up the whisk with some of the egg white mixture. Use your thumb and index finger (careful, it's hot!) to feel the mixture. If it still feels grainy, it needs more time on the stove. If it's smooth, you're good to go!
- Switch to a paddle attachment. Add the cubed butter one piece at a time at medium-high speed. Once all the butter has been incorporated, slowly pour in your melted (but not hot!) chocolate, salt, and vanilla extract.
- Assemble your cake and enjoy! I like to put small pieces of parchment paper under my first cake layer, that way when I frost the sides of the cake I don't get frosting all over my cake stand. Once decorated, I gently pull the strips of parchment paper away.
Swiss Meringue Buttercream Troubleshooting
- Make sure your cakes are completely cool when you frost them. I tend to make layer cakes the night before the fillings and frostings, that way I know I won't have any melting buttercream.
- When separating egg whites for the Swiss meringue buttercream, it's easier to separate them while the eggs are cold. What I suggest after a lot of testing is to take your eggs out of the fridge, separate the egg whites, then let them come to room temperature!
- If your egg whites aren't whipping up into stiff peaks, it could be there was some fat in your bowl (most likely, some egg yolk!) or on the whisk attachment. I make sure all of my tools aren't completely clean, and I also will separate the eggs into a separate bowl so if one egg breaks, it doesn't 'contaminate' all the other eggs I've separated.
- One issue people come across is their buttercream looking like it's curdling or separating. After making this type of buttercream countless times, I can safely say you just need to keep mixing it and it should come together. If it just gets thicker, then the butter you added may have been too cold. To fix this, place the mixing bowl back on the saucepan with simmering water for 1-2 minutes, then place it back in the mixer.
Recipe
Yellow Birthday Cake with Chocolate Swiss Meringue Buttercream
Equipment
- Two 8 inch cake pans
Ingredients
Vanilla Cake
- ⅓ cup (75 grams) unsalted butter room temperature
- 1 ⅔ cup (333 grams) white sugar
- ¼ cup (50 ml) neutral oil
- 4 large eggs room temperature
- 3 teaspoons vanilla extract
- 2 teaspoons baking powder
- 1 ½ teaspoons kosher salt
- 2 ¼ cups (270 grams) all purpose flour
- 1 cup (227 ml) buttermilk room temperature
Chocolate Swiss Meringue Buttercream
- 8 oz (225 grams) semisweet chocolate melted and cooled
- 1 cup (200 grams) white sugar
- 4 large (135 grams) egg whites room temperature
- 1 ⅓ cups (300 grams) unsalted butter room temperature and cubed
- ½ teaspoon kosher salt
- ½ teaspoon vanilla extract
Instructions
Vanilla Cake
- Preheat the oven to 350℉/175℃. Grease and line two 8-inch baking pans with parchment paper and set aside.
- In a stand mixer fitted with the paddle attachment, cream the room temperature butter with the oil and sugar until creamy on medium speed. This will take about 2-3 minutes, and it'll look a bit grainy and fluffy.⅓ cup (75 grams) unsalted butter, 1 ⅔ cup (333 grams) white sugar, ¼ cup (50 ml) neutral oil
- Add the eggs one at a time, beating well and scraping the bowl after each addition.4 large eggs
- Mix in the vanilla extract.3 teaspoons vanilla extract
- In a small bowl, whisk together the flour with the baking powder and salt2 teaspoons baking powder, 1 ½ teaspoons kosher salt, 2 ¼ cups (270 grams) all purpose flour
- Add ⅓ of the flour mixture, then mix on low. Add ½ the buttermilk. Repeat once more, then end with the flour mixture.1 cup (227 ml) buttermilk
- Pour the smooth cake batter into the prepared pans.
- Bake for 30-35 minutes, or until a toothpick inserted comes out clean. Let the cakes cool in the pans for 10-15 minutes before removing and letting them cool completely on wire cooling racks.
Make Frosting
- Fill a medium saucepan with an inch of water and bring to a simmer. Combine the sugar and egg whites in a large mixing bowl (if you have a stand mixer, you'll want to use that bowl), set the bowl above the simmering water. Make sure the bowl is completely clean before using, if there is any fat in the bowl then this meringue buttercream won't work!1 cup (200 grams) white sugar, 4 large (135 grams) egg whites
- Heat, whisking constantly, until the sugar dissolves. The mixture will go from a yellowy, granular substance to white and opaque, this takes about 5 minutes. I recommend taking a pastry brush to brush the sides of the bowl so all of the sugar is getting dissolved. Using a thermometer, it should read 140°F/60 C. If you don't have a thermometer, when you pull the whisk up feel the mix with your fingers - if it is no longer grainy then it is ready for the next step.
- Put the bowl into your stand mixer with a whisk attachment and beat on medium-high until you get a glossy meringue with stiff peaks - about 10-15 minutes. Note it can take up to 20 minutes if the weather is hot and humid. You'll want to be beating the mixture until the bowl is completely cool. If the bowl or meringue is too warm it will melt the butter.
- Switch to paddle attachment. Add butter one piece at a time, allowing it to incorporate fully, while still at medium-high speed. This should take 8-12 minutes. When you've added all the butter and the mixture looks smooth, slowly pour in the chocolate, vanilla extract and salt. Give it one final mix using a rubber spatula to make sure all of the chocolate is incorporated.8 oz (225 grams) semisweet chocolate, 1 ⅓ cups (300 grams) unsalted butter, ½ teaspoon kosher salt, ½ teaspoon vanilla extract
- Frost your cake and enjoy!
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Unsure baker says
This cake looks so amazing I think I'm going to have to give it a go!! How does it look so spongy and soft in a photo?!