3 cups (about 15 ounces) all-purpose flour
1 teaspoon table salt
16 tablespoons (2 sticks) unsalted butter, at room temperature
3/4 cup granulated sugar
2 tablespoons grated zest from 2 lemons
2 tablespoons chopped fresh rosemary
1 large egg
1 teaspoon vanilla extract
Turbinado sugar, for sprinkling
Whisk the flour and salt together in a medium bowl. In the bowl of a stand mixer fitted with the paddle attachment, beat together the butter and sugar on medium speed until the mixture is light yellow and fluffy, about 3 minutes. Add the lemon zest and rosemary, and mix for 30 seconds. Add the egg and vanilla, and mix for1 minute. Reduce the mixer speed to low and gradually add the flour mixture. Mix until the dough just comes together. Do not overmix.
Turn the dough out onto a work surface that has been covered with a piece of parchment or wax paper. Form dough into 2 logs 10 inches long and 1 1/4 inches in diameter. Wrap in parchment paper or wax paper with an outside wrapping of aluminum foil and chill.
Adjust oven rack to middle posision and preheat the oven to 350°F. Remove the dough from the refrigerator; peel off aluminum foil and parchment or wax paper, and put the dough on a cutting board. Slice the dough into 1/4-inch thick rounds. Place the cookies on a parchment-lined baking sheet and sprinkle a pinch of Turbinado sugar on top of each cookie.
Bake the cookies for 12-15 minutes, until they are slightly golden around the edges. Transfer the cookies to a wire rack to cool completely.