Pistachio Chocolate Macarons

Directions

• Let egg whites stand at room temperature for 30 minutes. Pulse confectioners' sugar and pistachios in a food processor until powdery.
• Preheat oven to 350°. Add salt to egg whites; beat on medium speed until soft peaks form. Gradually add sugar, 1 tablespoon at a time, beating on high until stiff peaks form. Fold in pistachio mixture.
• Cut a small hole in the tip of a pastry bag or in a corner of a food-safe plastic bag; insert a star tip. Transfer pistachio mixture to bag. Pipe 1-in.-diameter cookies 1 in. apart onto parchment paper-lined baking sheets. Bake until lightly browned and firm to the touch, 10-12 minutes. Cool completely on pans on wire racks.
• Place chocolate in a small bowl. In a small saucepan, bring cream and corn syrup just to a boil. Pour over chocolate; whisk until smooth. Whisk in butter. Cool, stirring occasionally, to room temperature or until filling reaches a spreading consistency, about 45 minutes. Spread on the bottoms of half of the cookies; cover with remaining cookies.