In a large bowl, cream together vegan butter and sugar with an electric or stand mixer. Add in the Lighthouse Lemonade Cordial, salt, vanilla, and lemon zest. Then, add in the flour, mixing on low until a dough is formed.
Shape the dough into a disk and cover in plastic wrap. Refrigerate dough until firm, about 30 minutes.
Meanwhile, preheat oven to 350 degrees Fahrenheit.
Remove the dough from fridge and roll to ¼ inch thick. Use a cookie cutter of your choice to cut the dough into shapes. Bake cookies on a parchment-lined baking sheet for 10 minutes or until lightly golden on the edges.
Remove cookies from oven and let cool completely on pan.
Meanwhile, make lemon glaze by whisking icing sugar with Lighthouse Lemonade Cordial until smooth.
Holding each cooled cookie on its side, dip the top of the cookie into the lemon glaze to coat. Let excess icing drip back into bowl.
Allow iced cookies to dry and sprinkle with finely chopped pistachios. Let stand until set, about 1 hour.
Store cookies in an airtight container for up to a week or freeze.