This fluffy pistachio buttercream pairs exceptionally well with chocolate cake. If you love pistachios, you’ll love this buttercream!
2 sticks butter, room temperature
2 egg whites, room temperature
¼ teaspoon cream of tartar
1 cup powdered sugar
½ cup granulated sugar
⅓ cup pistachios, very finely ground
2 drops green food coloring
Beat the egg whites until foamy, add the cream of tartar.
Beat on medium speed until soft peaks form, then add the granulated sugar
On high speed, beat the egg whites until stiff and glossy, about 2-3 minutes.
With the paddle attachment and the mixer on medium speed, add the butter a few tablespoons at a time, mixing well after each addition.
Add the powdered sugar and turn the mixer on high speed.
Beat the buttercream until light and fluffy, then add the pistachios and food color and keep beating for another 1-2 minutes.