Vegan Lemon Shortbread Cookies

Ingredients
2 1/2 cups all-purpose flour
1/2 teaspoon kosher salt
3/4 cup vegan butter, softened (such as Earth Balance or Miyoko’s)
3/4 cup granulated sugar
zest from two lemons
1 teaspoon vanilla extract
4 tablespoons aquafaba (the liquid from a can of chickpeas)
1 1/4 cups powdered sugar
2 Tablespoons fresh lemon juice