block with a long, sharp serrated knife (you can warm the knife in hot water and wipe dry for cleaner cuts). Then, cut the block into small rectangular or diamond-shaped cookies (typically about 1 inch wide by 1.5-2 inches long).

Preheat Oven & Prepare Pans: Preheat oven to 350°F (175°C). Grease and line three 13x9 inch jelly roll pans (or similar sized baking sheets) with parchment paper, leaving an overhang on the sides for easy removal.

Prepare Almond Paste Mixture: In a large bowl or the bowl of a stand mixer, beat the crumbled almond paste and granulated sugar together on low speed until the almond paste breaks down and resembles coarse sand. Add the softened butter and beat on medium speed until light and fluffy.

Add Egg Yolks & Extract: Beat in the egg yolks one at a time, then stir in the almond extract (if using).

Combine Dry Ingredients: In a separate bowl, whisk together the all-purpose flour and salt.

Whip Egg Whites: In a clean, grease-free bowl, beat the egg whites with an electric mixer on high speed until stiff peaks form.

Combine Batters: Gradually add the flour mixture to the almond paste mixture, mixing on low speed until just combined. Then, gently fold in about one-third of the whipped egg whites to lighten the batter. Fold in the remaining egg whites in two more additions, being careful not to overmix and deflate the volume.

Divide & Color Batter: Divide the batter equally into three separate bowls (use a kitchen scale for precision, about 1.5 cups or 450g per bowl). Tint one bowl of batter red with red gel food coloring and another bowl green with green gel food coloring, leaving the third bowl plain (white). Mix gently until the color is uniform.

Spread & Bake Layers: Spread each colored batter evenly into one of the prepared pans, using an offset spatula to create a thin, even layer. Bake each layer for 10-12 minutes, or until the edges are lightly golden and a toothpick inserted into the center comes out clean. Be careful not to overbake, as the layers are thin.

Cool Layers: Let the cake layers cool in their pans on a wire rack for about 10 minutes before using the parchment paper overhang to lift them out and transfer them to cool completely on the racks.

Assemble Cookies: Once completely cool, carefully invert the green layer onto a large piece of parchment paper or a clean cutting board. Spread half of the warmed jam evenly over the green layer. Top with the white (plain) layer, pressing gently. Spread the remaining jam over the white layer. Top with the red layer, ensuring it's aligned.

Press & Chill: Wrap the assembled layers tightly in plastic wrap. Place another baking sheet or a flat board on top, and weigh it down with something heavy (like a few cookbooks). Refrigerate for at least 4 hours, or preferably overnight, to compress the layers and allow flavors to meld.

Coat with Chocolate: Unwrap the chilled cookie block. Melt the chopped dark chocolate in a double boiler or in the microwave in short intervals, stirring until smooth. Pour half of the melted chocolate over the top (red) layer and spread it into a thin, even coat using an offset spatula. Let the chocolate set completely (you can refrigerate for 15-20 minutes to speed this up).

Once the top chocolate layer is set, carefully flip the block over. Coat the bottom (green) layer with the remaining melted chocolate, spreading evenly. Let this layer set completely.

Cut Cookies: Once both chocolate layers are firm, trim the uneven edges of the cookie

Enjoy: Your authentic Italian rainbow cookies recipe is complete! Store in an airtight container.