In a stand mixer fitted with a paddle attachment cream together the butter and sugar. Add in the lemon extract, salt and zest. Lastly add in the flour, mixing on low until the dough comes together. Shape the dough into a disk and wrap in plastic wrap. Cover and refrigerate for at least 2 hours up to overnight.
Preheat oven to 350 degrees.
Roll the dough to ¼ inch thick. Cut out with fluted square cutter, or other desired shapes. Place the cookies on a parchment lined baking sheet and bake for 10-11 minutes or until very lightly browned on the edges.
Transfer the baked cookies to a cooling rack. Allow to cool completely.
Melt the white chocolate chips and shortening together in the microwave. Heat for 30 seconds at a time, stirring in between, until completely smooth. The shortening makes the melted chips a little thinner and easier to dip, but it is completely optional.
Dip half of each cookie in the melted chocolate. Immediately sprinkle with pistachios. Place the finished cookies on a cookie sheet lined with a piece of waxed paper or parchment to finish drying. The process can be sped up by putting the cookies in the refrigerator until the chocolate hardens.
The calories shown are based on the recipe making 30 cookies, with 1 serving being 1 cookie. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information.**