Favorite Vanilla Bean Cupcakes with Vanilla Bean Meringue Buttercream

My Favorite Vanilla Bean Cupcakes with Vanilla Bean Buttercream: soft and airy vanilla bean cupcakes have a moist, fine crumb.  Topped with a silky smooth vanilla bean buttercream, these are the best cupcakes I've ever made.  

Back in January, I decided that it was time for me to master the Holy Grail of frostings: Swiss Meringue Buttercream.

What makes Swiss Meringue Buttercream so special?  In my opinion, it's that perfect combination of taste, texture, and presentation.  Taste: Swiss Meringue Buttercream (SMB, as it's often abbreviated) is much less sweet than a traditional American buttercream.  I have the world's sweetest sweet tooth, but even so, I find certain frostings to be too sweet.  Traditional American buttercream has 4-5 cups of sugar for every cup of butter.  By contrast, SMB has about a cup of sugar for every cup of butter.  Because the sweetness is so subtle, SMB is a good choice if you'd like to enhance your frosting with a delicate flavor such as almond, vanilla bean, coconut, or any fruit flavoring.  Texture: Swiss Meringue Buttercream achieves a light, airy, silky-smooth texture that is unrivaled in any other butter-based frosting.  I've heard people say that eating SMB is like biting into a cloud.  Those folks are 100% right; it's that fluffy.  Presentation: Despite the delicate texture, SMB is surprisingly stable once piped.  It can be piped using any shape of metal decorating tip and the frosting will have a crisp, clean edge.  A cake or cupcake decorated with SMB can be left at room temperature for hours without any ill effects to the frosting (the same can't be said for whipped cream frostings or cream cheese frosting, for instance).  For this reason, it's a great option for special occasion cakes that need to be prepared in advance.

When Swiss Meringue Buttercream turns out well, it's sheer perfection.  The first time I tried my hand at SMB, it worked like a charm.  But it can be a little high maintenance.  In fact, the next seven times I tried SMB, each batch failed miserably.  I mixed up batch after batch of soupy buttercream that never emulsified properly, wasting pounds of pricey European butter and dozens of egg whites.  Those batches were such a disappointment that I almost titled this post, "Seven Batches of Failed Buttercream."  But I didn't want to scare you off, because SMB is worth all the trouble.  

After all that frustration, I decided to seek out the professionals.  Professional pastry chefs, that is.  When I took the cupcake class at ICE last weekend (read about it here), my primary goal was to learn why I was having so much trouble with SMB.  The course description said we would learn how to make a "Foolproof Meringue Buttercream."  Sign me up.  A foolproof recipe was exactly what I needed.

After that class, I made three more batches of SMB, all of which turned out perfectly.  I feel like I've finally conquered my nemesis.  That deserves some celebratory pom-poms, no?

Here are a few hints for a successful Swiss Meringue Buttercream.  Some of these I learned during the class, and some I picked up through my own experimentation.  

Tips for Making Swiss Meringue Buttercream

• When cooking the egg whites, they should be placed in a mixing bowl over gently simmering water.  If the water is at a full boil, you could end up with scrambled egg whites. 
• When cooking the egg whites, be certain that you whisk constantly, but very gently.  You don't want to overbeat them so early in the process. 
• Before adding the butter, your whipped egg whites must be absolutely cool.  If they are even slightly warm, they will melt the butter.
• The temperature of the butter is key.  I achieved best results when using butter that is slightly softer than Play-Doh, but not as soft as Silly Putty (sorry, I know that's a strange way to describe butter).  
• European-style butter is preferable because of the higher fat content. 
• After adding all the butter (step 4, below), your frosting may be a bit too loose and liquid-y.  At this stage, my frosting often has the consistency of custard, especially if my kitchen is warm from the heat of the oven.  Simply refrigerate the frosting, in its mixing bowl, so that the butter fats will re-solidify.  After 15-20 minutes, remove the mixing bowl from the fridge, and continue mixing on the lowest speed.  Once frosting begins to come together, increase to medium speed and beat until light and airy. 

(click here for printable recipe)

Favorite Vanilla Bean Cupcakes with Vanilla Bean Meringue Buttercream

(Cupcakes adapted from Rose Beranbaum's The Cake Bible.  Frosting technique adapted from Nick Malgieri, who designed the cupcake course at ICE)

Cook Time: 20 minutes

Total Time: 2 - 2.5 hours

Ingredients

For the cupcakes:

• 2/3 cup milk or buttermilk, room temperature
• 3 egg whites, room temperature
• 1 1/2 tsp. vanilla extract
• 1/3 vanilla bean, with seeds scraped out
• 2 cups flour*
• 1 cup sugar
• 2 1/2 teaspoons baking powder
• 1/2 teaspoon salt
• 10 tablespoons butter
• 2 tablespoons Greek yogurt

For the buttercream:

• 3 egg whites, at room temperature
• 1 cup sugar
• small pinch of salt
• 2 sticks butter, softened and cut into cubes
• 2/3 vanilla bean, with seeds scraped out
• 1/4 cup powdered sugar, sifted (optional)

Instructions

For the cupcakes:

1. Preheat oven to 350 degrees.  Line standard muffin tins with paper liners.  Spray a paper towel with cooking spray, and wipe around the edges of each cavity on the muffin tin.  
2. In a small bowl, add egg whites, vanilla extract, and vanilla bean; mix lightly with a fork and set aside (it's fine if the vanilla bean clumps together at this point). 
3. In a large bowl, combine flour, sugar, baking power, and salt.  Whisk together lightly to aerate.  Add milk, butter, and Greek yogurt.  With a hand mixer, beat on medium speed for approximately 2 minutes until fully incorporated.  Add egg mixture, in three additions, beating for approximately 20-30 seconds after each addition.  Batter will be quite thick. 
4. Using a measuring cup, fill tins with a scant 1/4 cup batter for each cupcake.  Do not overfill.  Bake for 20-22 minutes, or until cake tester comes out mostly clean (it's fine if there are small crumbs attached to the cake tester, as the cupcakes will continue to bake once they've been removed from the oven). 
5. Cool for 3-5 minutes in the tin.  Then, remove to wire cooling racks and cool completely before frosting. 

For the frosting:

1. Fit stand mixer with whisk attachment.  Set aside.  Fill a medium saucepan with 1-2 inches of water, and bring to a gentle simmer.  
2. Put egg whites, sugar, and salt into a heatproof bowl of a stand mixer.  Whisk gently by hand, then set bowl on top of saucepan with simmering water (be certain that the water does not touch the bottom of the mixing bowl.)  Continue heating, whisking gently and consistently, until egg whites reach 140 degrees Fahrenheit.  The egg whites should be white and smooth, rather than grainy.  This may take 5-7 minutes. 
3. Once egg whites have reached 140 degrees, remove from heat and use stand mixer to whip egg whites on medium speed for approximately 5 minutes.  Egg whites should become thick and begin to increase in volume; the side of the bowl should feel mostly cool.  Remove whisk attachment and switch to paddle attachment.  Scrape down side of bowl with rubber spatula.  Beat on low speed until egg whites are completely cool.  
4. With mixer on low speed, add butter, 2 Tablespoons at a time, until all butter has been added. 
5. If frosting has become too warm and has a loose consistency, refrigerate in the mixing bowl for 15-20 minutes to allow the milk fat to re-solidify.  Remove from fridge after 15-20 minutes, and continue to beat on low speed with paddle attachment.  Frosting should begin to come together with a light and fluffy texture. 
6. Increase speed to medium and continue beating for 2-3 minutes, until frosting is light, fluffy, and smooth.  Add in seeds from vanilla bean.  If desired, add in 1/4 cup powdered sugar.  Beat once more until fully incorporated.
7. If cupcakes have cooled, frost immediately.  If not using buttercream immediately, cover with plastic wrap and refrigerate.  Bring to temperature and re-whip before using. 

Yield: 16-18 cupcakes

Notes: It's fine to use either cake flour or all-purpose flour in this recipe.  I prefer to use 1 cup cake flour and 1 cup all-purpose.  

(click here for printable recipe)

Thanks for reading, friends!  I hope some Swiss Meringue Buttercream is in your future!