Here’s what you will need:
Pistachio Shortbread Cookies:
3 sticks unsalted butter, softened
1 cup sugar, plus extra for sprinkling
1 teaspoon vanilla extract
3 1/4 cups all-purpose flour
1/4 cups pistachios, very finely chopped
1/8 teaspoon salt
1 stick butter, softened
1 1/2 cup powdered sugar
3 tablespoons special dark cocoa powder
2 tablespoons milk
1 tablespoon vanilla
6 ounces dark chocolate
1 tablespoon Crisco
1/8 cup pistachios, coarsely chopped
In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter and 1 cup sugar until combined. Then add the vanilla.
Next add the flour, pistachios, and salt to the mixture. Mix on low speed until the dough starts to come together. Shape the dough into a flat disc, wrap in plastic and chill for at least 30 minutes.
Once the dough is chilled, preheat the oven to 350 degrees F.
On a lightly floured surface roll out the dough so that it is 1/4-inch thick. Cut out the cookies with a round cookie cutter or the top of a round glass. Place the cookies on an ungreased baking sheet and sprinkle with sugar. Bake for 15 to 18 minutes, until the edges begin to brown. Allow to cool at room temperature.
To make the filling, in your mixer fitted with the whisk attachment, combine the butter, powdered sugar, cocoa powder, milk, and vanilla. Mix until smooth. If necessary, you can add more milk for a smoother filling or more powdered sugar to stiffen it up.
Once the cookies are cool, fill a piping bag or a plastic baggie with the chocolate filling. Pipe onto half of the cookies. Then top with a second cookie and gently press until the filling spreads to the edges.
For the drizzle, melt the chocolate chips and shortening in a microwavable bowl (or in a double broiler). Allow the mixture to cool slightly, then transfer to a plastic bag. Snip off a tiny portion of one corner of the bag and drizzle the chocolate on top of the cookies. Sprinkle with chopped pistachios for a garnish.