Total time: About 1 hour, plus chilling and cooling times
Servings: Makes about 3 dozen sandwich cookies
1 cup (4 ounces) sifted flour
1/3 cup sugar
2/3 cup finely chopped pecans or hazelnuts
1/2 cup (1 stick) softened butter, plus 2 tablespoons butter, divided
1/3 cup sifted powdered sugar
1 ounce melted chocolate
1. In a large bowl, sift together the flour and sugar. Stir in the chopped nuts until evenly combined, then blend in one-half cup butter using a pastry blender. Cover and refrigerate the dough until well-chilled, at least 1 hour.
2. Heat the oven to 375 degrees. On a floured surface, roll the dough to a thickness of slightly less than one-eighth inch, and cut into 2-inch rounds.
3. Place the cookies on an ungreased baking sheet, approximately 1 inch apart, and bake until barely browned, about 7 to 10 minutes.
4. Remove the cookies to a rack to cool completely.
5. While the cookies are cooling, make the filling: In a small bowl, mix together the 2 remaining tablespoons butter with the powdered sugar and melted chocolate until fully combined.
6. Spread one-half teaspoon filling over the base of 1 cookie. Place a second cookie over the filling to make a sandwich. Repeat until all the cookie sandwiches are made. Store the cookies in an airtight container. The cookies can be made up to 2 months ahead (unfrosted) and frozen; thaw before frosting.
Each of 36 sandwich cookies: 69 calories; 1 gram protein; 6 grams carbohydrates; 0 fiber; 5 grams fat; 2 grams saturated fat; 8 mg. cholesterol; 3 grams sugar; 1 mg. sodium.