Sally Sampson’s Citrus Shortbread Cookies

Recipe yields about six dozen cookies

Ingredients
2/3 cup confectioners' sugar
2/3 cup white sugar
Grated zest of 6 well-washed lemons or 4 lemons and 3 limes
4 sticks unsalted butter, at room temperature
1 tablespoon plus
1 teaspoon vanilla extract
2 teaspoons Kosher salt
4 1/2 cups all-purpose white flour

Ingredient Notes

1. Preheat oven to 325 degrees F.
2. Place both sugars and zest in a large bowl and mix until well combined and almost gritty. Using a mixer with a paddle attachment works well.
3. Add the butter and mix until smooth and creamy.
4. Scrape down the sides of the bowl, add the vanilla, and mix well.
5. Scrape down the sides of the bowl, add the remaining ingredients and mix until everything is well incorporated.
6. Scrape down the sides of the bowl and mix again.
7. Form into two 1 1/2 inch-diameter logs and cover with parchment paper.
8. Place the logs in a resealable GLAD® Food Storage Bag and refrigerate at least 1 hour and up to 2 days, or freeze up to 2 months.
9. Line a cookie sheet with parchment paper.
10. With the tip of a very sharp knife, cut 3/8-inch slices of the dough and place 2 inches apart on the prepared pan.
11. Transfer to the oven and bake until the cookies are just beginning to brown on the edges, about 20 minutes.
12. Transfer to a wire rack to cool.
13. Let the cookie sheet cool completely between batches and repeat with the remaining dough.