Lemony Slice-And-Bake Cookies

For cookies

Step 1: Whisk flour and salt in a medium bowl.

Step 2: Using an electric mixer on medium-high speed, beat butter, sugar, lemon zest, and

Step 3: Vanilla in a large bowl, occasionally scraping down sides, until light and fluffy, about 3 minutes. Add egg yolks; beat just to blend.

Step 4: Reduce speed to low; add flour mixture and beat, occasionally scraping down sides, just to blend.

Step 5: Divide dough in half; roll each half into a 10"-long log about 1 3/4" in diameter. Wrap in plastic and chill until firm, about 1 hour.

Step 6: Arrange racks in lower and upper thirds of oven; preheat to 350°F. Line 2 baking sheets with parchment paper.

Step 7: Unwrap 1 dough log. Using a sharp, lightly floured knife, cut log into 1/4"-thick rounds. Transfer to prepared sheets, spacing 1" apart.

Step 8: Bake until cookies are firm and golden brown around edges, 16-18 minutes. Let cool for 1 minute, then transfer to wire racks and let cool completely.

Step 9: Repeat with remaining dough log, using cooled baking sheets and new parchment paper.

Step 10:

For icing

Step 11: Whisk sugar and 2 tablespoons juice in a small bowl, adding more juice by 1/2-teaspoonfuls if too thick.

Step 12: Add coloring, if desired. Spread or drizzle icing over cookies.

Step 13: Decorate as desired with sanding sugar. Let stand until icing sets, about 10 minutes.

Step 14: Store airtight at room temperature.