Preheat the oven to 330°F or (165°C) and place the oven rack on the upper position and the other on the bottom. Position oven racks in the upper third and lower third of the oven.
Line and grease three 9X12-inch quarter baking pans.
Add the marzipan (almond paste), sugar, and half the butter into a bowl of a stand mixer with the paddle attachment and beat on medium speed for 90 seconds. Add the rest of the butter and continue to beat for 4-5 minutes or until the mixture is smooth and fluffy.
Add the egg yolks one at a time while the mixer is running at a slow speed, then add the vanilla e and almond and beat until the mixture is well combined. Scrape the sides as needed.
In a separate large clean dry bowl add the egg whites and beat on high speed with a hand mixer until stiff peaks are achieved about 5-6 minutes.
Gently fold the whipped egg whites with the cake batter in 3 additions until the mixture is well combined.
Divide the batter equally into 3 bowls, or scale the cookie batter at 410 grams into the bowls.
Add 6-8 drops of green food coloring into one bowl, and the same amount of red coloring into another bowl, and stir together until combined.
Pour each of the batters into the lined baking sheets, and spread evenly using offset spatulas.
Place the baking pans into the oven and bake for 22-25 minutes or until a toothpick comes out clean. Rotate the trays halfway during the baking to ensure even baking.
Place 2 pans on the upper third rack, ensuring the pans are not touching, and 1 pan on the lower third oven rack.
Remove from the oven and allow the cookie slabs to cool in the pan for about 20 minutes.
Spread 1/2 of the strawberry jam over the top of the green cake slab, then turn over the white cake slab onto it and remove the parchment paper. Spread the rest of the jam on the white cake, then flip the red cake slab onto it, and keep the parchment paper on top.
Place an empty tray on top and add some weights to it. You can use, plates, bags of milk, or canned vegetables. This will help compress the layers of the cookies. Refrigerate for at least 3-4 hours, or overnight.
Remove the tray from the refrigerator, then remove the weights and parchment paper. Flip the cake onto a large cutting board. Slowly remove the parchment from the green layer cake, then invert the cake again so the green slab is the first layer. Trim the sides of the cake with a serrated knife.
Place the chocolate chips into a microwave-safe bowl and melt using 25-second intervals stirring between each interval.
Once chilled, remove the weights and plastic wrap. Place a large cutting board on top of the stack and invert. Carefully remove and discard the parchment paper from the green layer.. Using a serrated knife, trim the edges to straighten. Place the stack, green layer up, on a wire rack set inside a large, rimmed baking sheet.
Pour the melted chocolate over the cake and spread it evenly throughout the top of the cake with an offset spatula. Let it stand for a few 3-4 minutes, then using a fork create a wavy effect by swirling the fork over the chocolate.
Place the rainbow cookie into the refrigerator for one hour.
Remove the slab from the fridge and slice the cake into 2-inch square pieces.
You can store the cookies at room temperature in an air-tight container for up to one week.
Enjoy your festive Italian Rainbow cookies!
This recipe is outstanding, my rainbow cookies were perfect.
Easy to make, insstructions are precise and thorough.
Excellent!!
Made this recipe but swapped the flour with gluten free flour and they turned out great.