Martha Stewart’s white cupcakes with Swiss meringue buttercream

Winter Rose cupcake (which uses Martha Stewart's recipe below)

I love baking. I do. My favourites are anything chocolate (I have a delicious never-fail chocolate mud cake from Super Food Ideas that I will share sometime). I also love making muffins, and I have my own Cordon Bleu muffin recipes. But these days, I am so into cupcakes. And below is my favourite cupcake recipe: Martha Stewart's white cupcake with Swiss meringue buttercream.

This recipe is a tad expensive, as in you will use 5 egg whites for the cupcake and 5 extra egg whites for the icing... but this is when you can also make the delicious lemon cake I posted earlier today. The egg whites make the cupcake very light (and slightly guilt-free, hehe). The egg whites also somehow hold the icing stronger, particularly for hot climate like Bali.

 

White cupcakes

Makes about 36 cupcakes
 
3 ¼ cups sifted cake flour (not self raising)

1 ½ tablespoons baking powder

¼ teaspoon salt

1 tablespoon pure vanilla extract

1 cup plus 2 tablespoons milk

½ cup plus 6 tablespoons (1 ¾ sticks = 7 ounces = 200 grams) unsalted butter, room temperature

1 ¾ cups sugar

5 large egg whites, room temperature

1. Preheat oven to 350F (180C). Line standard muffin tins with paper liners. Sift together cake flour, baking powder, and salt. Stir vanilla into milk

2. With an electric mixer on medium-high speed, cream butter until smooth. Gradually add sugar, beating until pale and fluffy. Reduce speed to low. Add flour mixture in three batches, alternating with two additions of milk, and beating until just combined after each.

3. In another bowl, with  electric mixer on medium speed, whisk the egg whites until stiff peaks form (do not overmix). Fold one third of the egg whites into batter to lighten. Gently fold in remaining whites in two batches.

4. Divide batter evenly among lined cups, filling each three quarters full (use ice cream scoop). Firmly tap the tins once on countertop to release any air bubbles. Bake, rotating tins halfway through, until a cake tester inserted in centers comes out clean, 18-20min.

5. Transfer to cool for 10min.

6. Spread with Swiss meringue buttercream (see below)

Swiss meringue buttercream

Makes 5 cups

Swiss meringue, not yet added with butter. It has to be glossy like this

Ingredients

5 large egg whites

1 cup plus 2 tablespoons (=250 grams) sugar

Pinch of salt

1 pound (4 sticks = 454 grams) unsalted butter, room temperature, cut into tablespoons (this sounds like A LOT of butter, but apparently, this amount IS required to hold the icing together)

1.5 teaspoon pure vanilla extract

Directions

1. In a heatproof bowl  (I use my Pyrex glass bowl, see picture above) set over a saucepan of simmering water, combine egg whites, sugar and salt. Cook, whisking constantly by hand until sugar has dissolved and mixture is warm to the touch. Mixture should feel smooth when rubbed between fingers.

2. Mix on low speed, gradually increasing to medium-high, until stiff (but not dry) peaks form. Continue beating until the mixture is fluffy, glossy and completely cooled.

Swiss meringue buttercream, after being added with butter

3. With mixer on medium-low speed, add butter several tablespoons at a time, beating well after each addition. (If frosting appears to separate after all the butter has been added, beat on medium-high speed until smooth again, 3 to 5 minutes more.) Beat in vanilla. Beat on lowest speed to eliminate any air bubbles, about 2 minutes. For tropical places like Bali, you might have to store the icing in the fridge before piping.

4. My own: divide the icing into two. Add mint oil and green natural colouring into the first half. Add red natural colouring into the second half.  

The mint and rose version. Yumm...

Happy baking! 

Note 16 Nov 2012:

If your SMBC (Swiss Meringue Buttercream) is curdled even after a long beating, try to put the Pyrex bowl (with the SMBC in it of course) over a pan of boiling water (the bowl should not touch the water; it should perch on it). As the frosting heats up, beat it on LOW speed. Click this for the explanation. 

Alternatively, put it on microwave for 15-20 seconds, then beat it on low speed as well. See this site for the explanation.