If Santa's elves grew citrus trees, these sparkling lemony bites would surely be among the branches. Our favorite in a year rich with cookies, these adorable little balls look like nothing found in any store. They melt in your mouth, leaving behind a lovely citric freshness. Roll them in brightly colored sanding sugar to make them twinkle like vintage ornaments.

　　

Ingredients

Makes about 4 dozen sandwich cookies

　　

For Cookies

1 1/3 cups all-purpose flour

　　2/3 cup cornstarch

　　1/4 teaspoon salt

　　2 sticks (1/2 pound) unsalted butter, softened

　　1/2 cup confectioners' sugar

　　1 tablespoon grated lemon zest

　　1 teaspoon vanilla

　　White and colored sanding sugars

　　

For Filling

1 cup confectioners' sugar

　　1 tablespoon grated lemon zest

　　1 tablespoon fresh lemon juice

　　2 tablespoons light corn syrup

　　1/2 stick (4 tablespoons) unsalted butter, softened

　　

Special Equipment:

a heavy-duty sealable bag

　　

Make Cookies:

Step 1

Preheat oven to 350°F with rack in middle. Line 2 large baking sheets with parchment paper.

　　

Step 2

Whisk together flour, cornstarch, and salt.

　　

Step 3

Beat together butter and confectioners' sugar with an electric mixer until pale and fluffy, then beat in zest and vanilla. At low speed, mix in flour mixture just until a soft dough forms.

　　

Step 4

Put sanding sugars in different bowls. Roll a scant teaspoon of dough into a ball and drop into sugar, turning to coat. Reshape if necessary and transfer to a baking sheet. Repeat, spacing balls 3/4 inch apart, until baking sheet is filled.

　　

Step 5

Bake until tops are slightly cracked but still pale (bottoms will be pale golden), 12 to 15 minutes. Transfer cookies on parchment to a rack to cool completely.

　　

Step 6

Form and bake more cookies on second baking sheet.

　　

Make Filling and Sandwich Cookies:

Step 7

Beat together all filling ingredients in a large bowl with an electric mixer at medium speed until combined well. Transfer to sealable bag and snip off a corner.

　　

Step 8

Turn over half of cookies and pipe about 1/2 teaspoon filling on flat side of each. Sandwich with remaining cookies, pressing gently.

　　Recipe Notes

　　1. The sugared dough balls should be chilled for 30 minutes or frozen for 5 to 10 minutes to help preserve their round shape. Keep the sandwiched cookies chilled.

　　2. The unsandwiched cookies keep, in a metal cookie tin, at a cool room temperature for up to 4 days.

　　From The Gourmet Cookie Book: The Single Best Recipe from Each Year 1941-2009 by Condé Nast Publications. Copyright © 2010 by Condé Nast Publications; photographs copyright © 2010 by Condé Nast Publications. Published by Houghton Mifflin Harcourt Publishing Company.