You will need:
1 cup unsalted shelled pistachios
1 1/4 cups unsalted butter, room temperature
6 ounces cream cheese, room temperature
3 cups sugar
6 large eggs, room temperature
2 teaspoons pure vanilla extract
3 cups all purpose flour
1 tablespoon coarse salt
3/4 cup coarsely chopped salted pistachios
Drippy icing (recipe follows)
1 1/2 cups unsalted pistachio slivers for garnish
1 cup plus 3 tablespoons confectioners' sugar, sifted
3/4 cup heavy cream
1 teaspoon fresh lemon juice
Whisk all ingredients in a small bowl until smooth
1. Preheat oven to 325F. Line standard muffin tins with paper liner. In a food processor, grind shelled pistachios to a paste.
2. With an electric mixer on medium high- high speed, beat butter, cream cheese and pistachio paste until fluffy, about 3 minutes. Reduce speed to medium-low. Gradually add sugar; beat until smooth, scraping down sides of bowl as needed. Add eggs, one at a time, beating until each is incorporated. Beat in vanilla. Reduce speed to low. Add flour and salt, beating until just combined. Fold in chopped pistachios by hand.
3. Divide batter evenly among lined cups, filling each three quarters full. Bake, rotating tins halfway through, until a cake tester inserted in centers comes out clean, about 30 minutes. Transfer tins to wire racks to cool completely before removing cupcakes. Cupcakes can be stored up to one day at room temperature, or frozen up to 2 months, in airtight containers.
4. To finish, place cupcakes on a wire rack set over a baking sheet; spoon icing onto each, and garnish with pistachio slivers. Cupcakes are best eaten the same day they are glazed; keep at room temperature until ready to serve.
I ended up using pistachios cut in half for garnish instead of the slivers. Also i slightly adjusted the consistency of the icing.