Lemon-Blueberry Cupcakes
 
 
Yield: 24 cupcakes
Ingredients
For the cupcakes:
  • 2¼ (255g) cake flour
  • 1 Tbsp (15g) baking powder
  • ½ tsp (3g) kosher or sea salt
  • 1¼ cups (295mL) buttermilk
  • 4 large egg whites
  • 1½ cups (312g) granulated sugar
  • 1 Tbsp lemon zest
  • 1 stick (4 oz/113g) unsalted butter, room temperature
  • ½ tsp vanilla extract
  • ½ tsp lemon extract
For the frosting:
  • 6 oz fresh blueberries
  • 1 Tbsp granulated sugar
  • 4 large egg whites
  • 1¼ cups (250g) granulated sugar
  • 3 sticks (12oz/340g) unsalted butter, at room temperature
Instructions
  1. Preheat oven to 350 F. Line two cupcake pans with paper liners and set aside.
  2. In a medium bowl, sift together the cake flour, baking powder, and salt. In a measuring cup, combine the egg whites and buttermilk and stir. Set aside.
  3. In a stand mixer bowl or other large mixing bowl, combine the sugar and lemon zest. Mix together with your fingers until the sugar is moist and lemon-scented. Add the butter and beat on medium speed until light and fluffy, about two minutes. Add the vanilla and lemon extracts and beat very briefly to combine. Add the dry ingredients in three additions, alternating with the milk/egg mixture, beginning and ending with the dry ingredients and mixing well between each addition. Beat on medium speed for about one more minute to thoroughly combine all ingredients. Divide batter evenly between cupcake tins, filling each about ⅔ to ¾ full. Bake for 18-20 minutes, until a toothpick inserted in the center comes out clean. Cool in pans for five minutes, then remove to racks to cool completely.
  4. To make the frosting, first blend the blueberries and 1 Tbsp sugar in a food processor or with an immersion blender. Refrigerate for at least an hour - the pureed berries will take on a jelly-like consistency.
  5. Fill a medium saucepan with about 2 inches of water and bring to a simmer over medium heat. Whisk egg whites and sugar together in the bowl of a stand mixer. Rest the mixer bowl over the saucepan, whisking constantly until sugar is completely dissolved and the mixture is thick and glossy (note: to completely pasteurize the egg whites, they must be heated to 140 degrees).
  6. Remove mixer bowl from heat and place on stand mixer. Using the whisk attachment, beat on high speed until cooled and the egg whites hold stiff peaks, about 8 minutes. Switch to the paddle attachment and add the butter two tablespoons at a time. Beat until fluffy and smooth, about 3-5 minutes. Add the pureed blueberries and continue beating until fully incorporated and smooth. Frost and serve.
Recipe by Baked In at https://www.baked-in.com/2012/04/04/lemon-blueberry-cupcakes/