I love summer flavors. Apparently, my mother also does! She asked me to make some lemon cupcakes for her a few months back. So for Mother’s Day I finally broke down and found a recipe I was happy with. And for the very first time I tried making a swiss meringue buttercream. These are really good and this buttercream compliments it well because the cake is so lemony (is that a word?) that the frosting tones it down! Here it is.
Yield: about 12 cupcakes
For the cupcakes:
1 1/8 cup flour
1 1/2 tsp baking powder
1/4 tsp salt
1/2 cup + 1/8 cup buttermilk
2 large egg whites
3/4 cup sugar
zest from one lemon
1/4 cup unsalted butter
1/2 tsp pure vanilla extract
1/2 tsp pure lemon juice (1/4 if lemon extract)
For the cupcakes:
Center a rack in oven and preheat to 350 degrees. Prepare pan with liners. Set aside.
Sift together flour, baking powder, and salt. Set aside. Whisk together milk and egg whites in a medium bowl. Put the sugar and lemon zest in a mixer bowl or another large bowl and rub together with fingers until sugar is moist and fragrant. Add butter and beat at medium speed for a full 3 minutes, until the butter and sugar are very light. Beat in extracts, then add one-third of the flour mixture, still beating on medium speed. Beat in half of the milk-egg mixture, then half of the dry ingredients. Add the rest of the milk-eggs, then the last of the dry ingredients. Divide the batter into prepared cupcake liners.
Bake for 18-22 minutes, until cupcakes are risen and springy to the touch.
For the frosting:
5 large egg whites
1 1/8 cup sugar
Pinch of salt
3.5 sticks unsalted butter, at room temperature (this is very important!)
4 tsp pure lemon juice (2 tsp if lemon extract)
Combine the egg whites, sugar, and salt in a heatproof bowl set over a pot of simmering water. Heat, whisking frequently, until the sugar has dissolved and the mixture reaches 160 degrees F.
Transfer the mixture to the bowl of a stand mixer, fitted with the whisk attachment. Beat on medium-high speed until stiff peaks form and the mixture has cooled to room temperature, about 8 minutes.
Reduce speed to medium and add the butter, 2 Tbsp at a time, adding more once each addition has been incorporated. Stir in the lemon extract and mix just until incorporated.