These very thin, very crisp cookies have a strong mocha flavor with just a hint of orange. It’s important to use Dutch-process cocoa, which is richer and darker than plain cocoa. Dutch-process powder is treated with alkali to help neutralize the cocoa’s natural acidity.

　　

Ingredients

makes about 4 dozen

　　1 1/2 cups all-purpose flour

　　1/2 cup unsweetened Dutch-process cocoa powder

　　1 1/2 teaspoons good-quality instant espresso powder

　　1/2 teaspoon coarse salt

　　1 cup (2 sticks) unsalted butter, room temperature

　　1 cup confectioners’ sugar

　　1 teaspoon finely grated orange zest

　　1 teaspoon pure vanilla extract

　　Coarse sanding sugar, for sprinkling

　　

Step 1

Sift together flour, cocoa powder, espresso powder, and salt into a medium bowl.

　　

Step 2

Put butter, confectioners’ sugar, orange zest, and vanilla in the bowl of an electric mixer fitted with the paddle attachment. Mix on medium speed until pale and fluffy, about 3 minutes. Reduce speed to medium-low, and gradually add flour mixture until just combined.

　　

Step 3

Transfer dough to a 12 by 16-inch piece of parchment paper; shape into a log. Roll in parchment to 1 1/2 inches in diameter, pressing a ruler along edge of paper at each turn to narrow the log and force out air. Transfer in parchment to a paper towel tube; chill at least 2 hours or overnight.

　　

Step 4

Preheat oven to 350°F. Cut log into 1/4-inch-thick slices; transfer to baking sheets lined with parchment paper. Brush tops with water; sprinkle with sanding sugar. Bake until set, 15 to 17 minutes. Cool on sheets on wire racks. Cookies can be stored in airtight containers at room temperature up to 1 week.

　　Martha Stewart's Cookies