Step 1

Begin by placing the butter in the bowl of a stand mixer fitted with a paddle attachment. Beat on a medium-low setting for about 30 second to loosen.

Step 2

Add the pistachio paste and beat for another 30 seconds until combined.

Step 3

Sift about half of the powdered icing sugar into the bowl of the mixer. Beat on medium-low until incorporated.

Step 4

Finish sifting the remaining powdered icing sugar into the bowl and return the mixer to a medium-low setting, adding the vanilla extract and milk. Beat for about 5 minutes until light and creamy.