KRANSEKAKE

Steps:

• Dough: Place almonds in a food processor and process to form fine crumbs, about 2 minutes. Add sugar and salt and process until well combined and powder-like, about 1 minute. Add egg whites and process until a dough forms (it will have the texture of cookie dough). Wrap tightly in plastic wrap and refrigerate overnight.
• Preheat oven to 300°F with oven rack in the middle. Brush a set of 6 kransekake molds with butter. Divide dough in half. Working with one half of dough at a time, cut into small portions and roll into ropes that are slightly thicker than the diameter of a pencil (about 3/8-inch-to-1/2-inch thick). Fit ropes into rings of 3 molds, trimming to fit. Place molds on an unrimmed baking sheet and bake until puffed and lightly golden brown, about 30 minutes.
• Transfer molds to a wire rack and let cool completely on baking sheet. Repeat shaping and baking process with remaining half of dough and remaining 3 molds. Carefully remove rings from molds.
• Royal Icing: In the bowl of an electric mixer fitted with the paddle attachment, combine confectioners' sugar and egg whites. Mix on medium-high speed until combined and thickened, about 8 minutes. If decorating with more than one color, divide icing into batches. Using the end of a toothpick, add food coloring until the desired shade is achieved.
• To Assemble: Sort rings in order of size. Fill a piping bag with icing and pipe a few dots onto the base of the largest ring and adhere to a cake plate. Pipe icing onto the base of next largest ring, and stack on top of the first ring. Repeat process, continuing to stack rings in decreasing size to form a tower of 18 rings. Decorate as desired. Allow icing to set before serving.