Lemon-Lime Buttermilk Cookies

1 ½ cups unbleached all-purpose flour

¼ tsp baking soda

¼ tsp salt

6 Tbsp. (3 oz.) unsalted butter, at room temperature

1 tsp lemon zest

¾ cup sugar

1 large egg

1 tsp vanilla

1/3 cup buttermilk

1/4 cup sugar

1 tsp lime zest

Preheat the oven to 350°F. Line cookie sheet with parchment (or spray with cooking spray)

In a medium bowl, whisk together the flour, baking soda, and salt.

In a small bowl, mix 3/4 cup sugar and 1 tsp lemon zest. Rub zest into sugar with your fingers.

Beat the butter until creamy. Add the lemon sugar, and beat until pale and fluffy. Add the egg, and beat well. Add the vanilla, and beat briefly again. Mix in half the flour mixture, then buttermilk, then the other half of the flour mixture, all at low speed. Scrape down the sides of the bowl with a spatula often. The finished dough should be smooth and a little bit sticky.

Drop the dough by spoonfuls onto the cookie sheet.

Mix 1/4 cup sugar and lime zest, rub zest into sugar.

Bake until the cookies are puffed and their edges are golden, about 11 to 15 minutes. Sprinkle immediately with lime sugar. Cool the cookies on the baking sheet for a minute; then transfer them to a wire rack.