- 2 cups powdered sugar, divided
- 1 1/4 cups slivered almonds
- 3 tablespoons natural unsweetened cocoa powder
- 1/3 cup plus 3 tablespoons egg whites (from about 3 large eggs), room temperature, whisked to loosen
- 1/4 cup sugar
- 3 1/2 ounces bittersweet chocolate (do not exceed 61% cacao), finely chopped
- 2 tablespoons (1/4 stick) cold unsalted butter, cut into 1/2" cubes
- 1/2 cup heavy cream
- 1 tablespoon finely grated orange zest
- 1/2 teaspoon ground cloves
- 1/8 teaspoon ground allspice
- 1/8 teaspoon kosher salt
- Gold dust (optional)
Ingredient infoGold dust is available at speciality food stores
Arrange racks in lower and upper thirds of oven; preheat to 325°. Line 3 rimless baking sheets with parchment paper. Pulse1 cup powdered sugar and almonds in a food processor until nuts are very finely ground (but not to a paste), 60–90 seconds. Add cocoa powder and remaining 1 cup powdered sugar; process to blend well. Sift mixture through a medium-mesh strainer into a large bowl; discard larger almond pieces remaining in strainer (if more than 1 Tbsp. remains, pulse nuts again in processor and re-sift).
Using an electric mixer, beat 1/3 cup egg whites in a medium bowl on medium speed until white and frothy, about 1 minute. With mixer on medium-low speed, gradually add sugar by teasponfuls. Increase speed to medium-high; beat until firm peaks form.
Stir in remaining 3 Tbsp. egg whites. Fold meringue into dry ingredients in 2 additions, mixing well between additions.
Spoon meringue into a pastry bag fitted with a 1/4" tip. (Alternatively, spoon into a plastic freezer bag, then cut 1/4" off a corner of bag.) Twist top of bag and pipe quarter-size rounds onto 2 of the 3 prepared baking sheets, spacing 1" apart. Let stand until tops appear dry, about 10 minutes.
Bake cookies, rotating sheets halfway through baking, until puffed and dry, about 16 minutes. Slide cookies on parchment onto a wire rack. Let cool completely. Repeat with remaining batter on third baking sheet.
Place chocolate and butter in a medium bowl. Bring cream just to a boil in a small saucepan over medium-high heat. Remove from heat; stir in orange zest, cloves, allspice, and salt. Pour hot cream mixture over chocolate and butter; whisk until smooth. Refrigerate until firm, about 20 minutes.
Spoon ganache into a pastry bag fitted with a 1/4" tip. (Alternatively, spoon into a plastic freezer bag, then cut 1/4" off a corner of bag.) Twist top of bag and pipe about 1 tsp. ganache onto flat side of 1 cookie, leaving 1/4"–1/8" plain border. Top with a second cookie, flat side down. Repeat with the remaining cookies and ganache. Brush tops with gold dust, if desired. Layer in an airtight container between sheets of parchment paper and refrigerator overnight. DO AHEAD: Can be made 2 days ahead. Keep chilled. Let return to room temperature before serving.