Saturday, May 08, 2010

May's Cupcake of the Month: Strawberry Cupcakes

I selected this month's cupcake from the last non-decorating centric section of Martha Stewart's Cupcakes I had yet to try: Piped and Topped. The decision was seconded by the lovely local organic strawberries in my CSA basket.

I was a little intimidated by the challenge the frosting seemed to pose for Jenny and Tina over at Friends Who Bake. They have tackled some way more intense recipes from this book than I could muster, so their tales of frosting woe sent up warning flags. While I believe they followed the recipe from the book, they link to the cupcake recipe on Martha Stewart's website which references a slightly different frosting recipe. So I did a little research into this whole Swiss Meringue Buttercream thing to see if I could troubleshoot the recipe.

Meanwhile, the book recommends using an open-star tip size Wilton 8B or Ateco 826. I didn't happen to have either of these on hand, so I went to my handy neighborhood cake baking supply house the Calico Cake Shop. They didn't have an 8B or an 826, so I got a Magic Tip 8FT, which is an open-star tip with more sharp points than the 8B/826. The very helpful woman who worked there also showed me the tip they use to frost their cupcakes, the Magic Tip 1F, the opening of which looks sort of a like an anorexic shamrock. In the picture above, the cupcake on the left was frosted with the 8FT and the cupcake on the right was frosted with the 1F. I think I prefer the look of the 1F. It's a bit closer to the picture in the book, too, if accuracy is all the rage. And after much swearing at my inability to neatly end the swirl of frosting, I figured out why the recipe suggests putting a couple of slices of strawberry on top: to hide the fact you can't neatly end the swirl of frosting. I didn't like the bunny ear look two slices of strawberry produced, so I tried to go with three or four slices.

I was hoping the Calico Cake Shop would have some sort of reusable cupcake transportation device, but all I could find (and easily pick up with a baby on my hip) were boxes with inserts to carry six cupcakes. They worked wonderfully, but I'm still going to look for a reusable solution. Also, they made people think the cupcakes were store bought . . . which is kinda annoying when you've slaved away for two days . . . but also kinda cool if they thought they were nice enough to be fancy store bought.

I made two dozen cupcakes, though the recipe yields 30. The frosting was barely sufficient to cover the two dozen I made and I didn't actually pile the frosting two inches high as shown in the book. So if you're really going for an accurate two inch high frosting for 30 cupcakes, you might want to double the frosting recipe, just to be safe.

Most of the independent taste testers at the faculty party gave the cupcakes rave reviews, but two very important taste testers in the under six years old category were NOT fond of this frosting one bit. I can completely understand their opinions as this is not the sugary sweet frosting you might expect from its color. It's kinda like how the filling for the New York Times Whoopie Pies was sorta "grown up" compared to the filling of the The Ultimate Chocolate Cookie Book's Chocolate Cream Sandwich Cookies. After various adults gratefully scraped the rejected frosting onto their own cupcakes, the cake portions of said cupcakes met with the under-six-years-old set's approval.

Swiss Meringue Buttercream Resources:
Smitten Kitchen's project wedding cake: swiss buttercream
Epicurious August 2004 Toba Garrett The Well-Decorated Cake Swiss Meringue Buttercream
New York Times March 17, 2009 Whoopie Pies Adapted from Zingerman’s Bakehouse, Ann Arbor, Mich.

Strawberry Meringue Buttercream very loosely adapted from Martha Stewart's Cupcakes: 175 Inspired Ideas for Everyone's Favorite Treat


  • 1 1/2 C (8 oz.) fresh strawberries, rinsed and hulled
  • 4 large egg whites
  • 1 1/4 C sugar
  • 1 1/2 C (3 sticks) unsalted butter, cut into 1/2 tablespoons, just barely room temperature

1. Puree strawberries in a food processor. Combine egg whites and sugar in a heatproof bowl set over a pan of simmering water. Clip a candy thermometer to the side of the bowl. Cook, whisking constantly by hand, until the mixture reaches 180 degrees and sugar has dissolved (the mixture should feel completely smooth when rubbed between your fingertips).

2. Transfer the sugar/egg white mixture to the room-temperature bowl of a standing electric mixer fitted with the whisk attachment. Whisk on high speed until completely cool (test by touching the bottom of the bowl). The mixture should have doubled in volume and become thick and shiny. This might take about 10 minutes.

3. With mixer on medium-low speed, add the butter 1/2 tablespoon at a time, mixing well after each addition. Once all of the butter has been added, slowly increase the mixer's speed every 10 seconds until you reach a medium-high speed. At this point, your frosting may appear to be a curdly soup (mine didn't, but I think that's due to waiting until the bowl was cool to the touch AND not taking my chopped up butter out of the fridge until sometime during step 2). Do not abandon hope. Continue whipping on medium-high speed. It should return to a lovely mayonnaise-like consistency.

4. Once all butter has been thoroughly incorporated, scrape down sides of bowl with a flexible spatula and switch to the paddle attachment. Continue beating on low speed until all air bubbles are eliminated, about 2 minutes. Add strawberries and beat on low until combined (Now this is where my frosting lost its luxurious consistency for a terrifying minute or so. I kept calm and mixed on and all was well . . . or so I thought). Keep buttercream at room temperature if using the same day, or transfer to an airtight container and refrigerate up to 3 days or freeze up to 1 month. Before using, bring to room temperature and beat with paddle attachment on low speed until smooth again, about 5 minutes (And this is where I nearly completely lost my junk. As soon as the paddle started rotating the frosting turned into a curdled mass of gross. I switched to the whisk attachment and slowly increased the mixer's speed every 10 seconds until I reached a medium-high speed. Then I walked away and had some quality rage followed by some deep breaths and brain storming what I could use instead to top these bad boys for the faculty party I was already late for. After about five minutes experiencing the five stages of grief, I went back to my mixer to find that it looked just fine.)

Strawberry Cupcakes adapted from Martha Stewart's Cupcakes: 175 Inspired Ideas for Everyone's Favorite Treat

  • 2 3/4 C all-purpose flour
  • 1/2 C cake flour
  • 1 T baking powder
  • 1 t salt
  • 1 C (2 sticks) unsalted butter, room temperature
  • 2 1/4 C sugar
  • 1 1/2 t pure vanilla extract
  • 3 large eggs
  • 1 egg white
  • 1 C milk
  • 2 C finely chopped fresh strawberries, plus about 10 more for garnish

1. Preheat oven to 350. Line standard muffin tins with paper liners. Sift together both flours, baking powder, and salt.

2. With an electric mixer on medium-high speed, cream butter, sugar, and vanilla until pale and fluffy. Add whole eggs and egg white one at a time beating until each is incorporated, scraping down sides of bowl as needed. Reduce speed to low. Add flour mixture in two batches, alternating with the milk, and beating until well combined. Fold in chopped strawberries by hand.

3. Divide batter evenly among lined cups, filling each three-quarters full. Bake, rotating tins halfway through, until golden, about 25 to 30 minutes. Transfer tins to wire racks to cool 15 minutes. Turn out cupcakes onto rack and let cool completely. Cupcakes can be stored up to 1 day at room temperature in airtight containers.

4. To finish, fill a pastry bag fitted with a large open star tip with buttercream. Pipe buttercream onto each cupcake, swirling tip and releasing as you pull up to form a peak. Just before serving, thinly slice remaining strawberries, and tuck a few pieces into the buttercream.

Previous Cupcakes of the Month:
January's Cupcake of the Month: Streusel Cupcakes
February's Cupcake of the Month: Martha's Meyer Lemon Cupcakes
March's Cupcake of the Month: Flourless Chocolate Cupcakes
April's Cupcake of the Month: Tres Leches Cupcakes

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tina_bakes said...

Hi Sarah!! Apart from the cake testers and a couple under-6 yr olds, did YOU like the cupcakes? what did you think of them? I thought they were the lesser good-tasting ones from the book. The one we chose last weekend, peanut butter and jelly those were GOOD! :)

Sarah said...

Hi Tina! I did like the cupcakes. If I got another unexpected ton of strawberries, I'd make them again. The cake part was particularly delicious. I'm not 100% convinced the frosting was worth the effort. A bit of whipped cream would be a simple lovely alternative.

I did a little research and think I've figured out why the strawberry swiss meringue buttercream collapses upon the addition of the strawberry puree. Here's a quote from Harold McGee's On Food and Cooking page 105:

"Water is seldom called for, but in small amounts it increases the volume and lightness of the foam. Because water thins the whites, however, it's more likely that some liquid will drain from the foam. Albumen diluted by 40% or more of its volume in water cannot produce a stable foam."

The 1 1/2 C of pureed strawberry, which is mostly water, certainly exceeds the volume of 4 egg whites. So I think what happens when you add the strawberry puree to the swiss meringue buttercream is the water from the puree destabilizes the egg white foam, which basically takes all the meringue-ness out of the frosting. That might also explain why the volume of frosting I produced from the recipe wasn't sufficient to cover 30 cupcakes.

Also, a plain vanilla swiss meringue buttercream would be a lovely complement to the strawberry cupcakes, and would reduce the likelihood of frosting drama.

Zed said...

Your cupcakes look delicious! I wish I lived closer... ;-) Regarding your wish for reusable transportation, last night I was talking with our friend Lisa, who is a pastry chef, and she recommended Snapware for reusable cupcake transportation. She has the 2 Layer Snap N Stack cupcake/cookie carrier and likes it a lot. She said she got it at Costco for less than than list price. The link is:
Hope that helps and I look forward to reading about more of your culinary adventures!