(Real) Pistachio Cupcakes with Brown Sugar Buttercream
Author: 
Recipe type: Dessert
Makes: 2½ - 3 dozen regular-sized cupcakes
 
Flavorful pistachio cupcakes made from scratch and topped with the best brown sugar buttercream.
Ingredients
Pistachio Cupcakes:
  • 4⅜ ounces (~1 cup) roasted and salted shelled pistachios (plus more for garnish)
  • 9⅝ ounces (~2½ cups) cake flour
  • 3½ ounces (3/4 cup) all-purpose flour
  • 1 tablespoon baking powder
  • 1 teaspoon baking soda
  • ¼ teaspoon table salt
  • 1½ cups ice cold water
  • ½ pound (1 cup / 2 sticks) unsalted butter, softened at room temperature
  • 13⅛ ounces (~1¾ cup) granulated sugar
  • 1 tablespoon vanilla extract
  • 4 x-large egg whites, separated
  • ¼ teaspoon cream of tartar
Brown Sugar Buttercream:
  • 4¼ ounces egg whites at room temperature (~4 large egg whites)
  • 1 pound 0.5 ounces light brown sugar (~1 cup, packed)
  • pinch of salt
  • ½ pound (1 cup / 2 sticks) of room temperature unsalted butter sliced into tablespoons
  • ½ teaspoon vanilla extract
Instructions
Pistachio Cupcake
  1. Pre-heat oven to 325; line muffin tins with cupcake liners and set aside
  2. In a food processor, pulse the pistachios just until they are coarsely chopped; remove 2 tablespoons and place in a large bowl
  3. Continue to pulse remaining pistachios until they are finely ground; be careful not to grind too long or they will begin to turn into more of a paste; add to bowl with other pistachios
  4. Sift flour, baking powder, baking soda and salt into the bowl of pistachios; whisk mixture and set aside
  5. In the large bowl of an electric mixer with the paddle attachment, beat butter and sugar on high speed until light and creamy (at least 5 minutes)
  6. Add 1 egg white and vanilla and mix until combined; scrape the sides of the bowl with a spatula
  7. Turn mixer down to the lowest speed and slowly add part of the dry and wet ingredients, starting and ending with the dry ingredients; do not overmix
  8. Remove bowl and set aside
  9. Use a clean bowl (I wipe mine down with white vinegar) and whisk attachment and whisk the 3 remaining egg whites and cream of tartar until soft peaks form (several minutes on medium-high speed)
  10. Carefully fold egg whites into batter just until combined
  11. Use a large cookie dough scoop or small ladle to evenly distribute batter into prepared tins
  12. Bake 14-16 minutes or until a toothpick comes out clean from center of cupcakes (I usually test 1 or 2 towards the center of the tin)
Brown Sugar Buttercream:
  1. Wipe down your metal mixing bowl, whisk attachment, whisk and candy thermometer with lemon juice or white vinegar to make sure they are all grease free
  2. Place mixing bowl over pot of shallow simmering water (do not want bowl in the water) with candy thermometer attached
  3. In that bowl, combine brown sugar and egg whites, whisking continuously until temperature measures 160 degrees (if you do not have a candy thermometer, you want the mixture to be warm and the sugar to be dissolved); this will take about 5 minutes
  4. Place bowl back on mixer and place a bowl of ice directly underneath to help the cooling process; use whisk attachment and beat meringue in medium speed until a creamy meringue is formed, it should be thick but not stiff; bowl should also cool down while you are mixing
  5. Once texture is right and bowl has cooled, reduce speed to low; add butter, 1 tablespoon at a time, until it is completely combined; whisk in vanilla
  6. Pipe or spread buttercream over cooled cupcakes as desired; sprinkle with extra chopped pistachios
Notes
If your buttercream is too wet, it may have been too warm; place bowl in fridge for 15-20 minutes and then mix again
Cupcakes slightly adapted from cake by Kitchen Trial and Error who adapted it from Baked Explorations
Buttercream adapted from Martha Stewart
Recipe by Keep It Sweet Desserts at http://www.keepitsweetdesserts.com/real-pistachio-cupcakes-with-brown-sugar-buttercream/