Step 1: Prepare Your Baking Pans and Oven

Begin by preheating your oven to 350°F. Line three baking pans of equal size with parchment paper. The parchment paper is essential because the thin cake layers can stick easily and may tear during assembly.

Having all three pans prepared before mixing the batter makes the process much smoother. Since the batter will be divided into three portions, it helps to have everything ready ahead of time.

Set the prepared pans aside while you make the batter.

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Step 2: Separate the Eggs

Carefully separate the four eggs, placing the whites in one large bowl and the yolks in another.

The egg whites play a major role in creating a lighter texture. Whipping them separately incorporates air into the batter and prevents the layers from becoming too dense.

Allow the eggs to sit at room temperature while you continue preparing the other ingredients. Room temperature eggs blend more easily and create a smoother batter.

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Step 3: Cream the Almond Paste and Sugar

Place the almond paste and granulated sugar into a large mixing bowl or the bowl of a stand mixer.

Mix them together until the almond paste breaks down into small pieces and begins combining evenly with the sugar. This step may take several minutes because almond paste tends to be firm and crumbly.

Continue mixing until the mixture resembles coarse crumbs. Properly breaking down the almond paste ensures the finished cookies have a smooth texture and even almond flavor throughout.

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Step 4: Add the Butter

Add the softened butter to the almond paste mixture.

Beat until the mixture becomes light and creamy. The butter should fully incorporate into the almond paste and sugar mixture, creating a fluffy base.

This creaming process adds air to the batter, which helps the thin cake layers bake evenly. Scrape down the sides of the bowl occasionally to make sure everything mixes uniformly.

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Step 5: Incorporate the Egg Yolks

Add the egg yolks one at a time while mixing.

Allow each yolk to fully blend into the batter before adding the next. The mixture should become smooth, rich, and slightly pale in color.

Taking your time with this step helps create a stable batter and prevents separation later on.

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Step 6: Add the Dry Ingredients

Add the all purpose flour and salt to the bowl.

Mix just until the flour disappears into the batter. Avoid overmixing because excessive mixing can develop gluten, resulting in tougher layers.

The batter should be thick, smooth, and evenly combined.

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Step 7: Whip the Egg Whites

In a clean bowl, beat the egg whites until stiff peaks form.

The whites should hold their shape when the beaters are lifted. Properly whipped egg whites provide structure and help keep the layers soft rather than heavy.

Take care not to overbeat them. The texture should be glossy and stable.

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Step 8: Fold the Egg Whites Into the Batter

Add about half of the whipped egg whites to the almond batter.

Gently fold them in using a rubber spatula. This first addition lightens the batter and makes it easier to incorporate the remaining whites.

Once mostly combined, fold in the rest of the whipped egg whites.

Use slow, gentle motions to preserve as much air as possible. The finished batter should look smooth and airy.

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Step 9: Divide the Batter Into Three Portions

Evenly divide the batter into three separate bowls.

One portion will remain plain, while the other two portions will be colored red and green to create the traditional Italian flag appearance.

Try to keep the portions as equal as possible so the layers bake evenly and maintain consistent thickness.

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Step 10: Color the Batter

Leave one bowl uncolored.

Add green food coloring to one bowl and red food coloring to another. Stir each portion until the color is evenly distributed.

Aim for vibrant colors because they will soften slightly during baking. The red and green layers should be bright enough to remain distinct after baking and assembly.

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Step 11: Spread the Batter Into the Pans

Transfer each batter portion into a prepared pan.

Using an offset spatula, spread the batter into an even layer. Since the layers are very thin, take your time to smooth the surface and reach all corners.

Even layers create a more professional appearance once the cookies are sliced.

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Step 12: Bake the Layers

Bake the layers for approximately 8 to 10 minutes.

The cakes should be fully set and lightly colored but not browned. Because the layers are thin, they bake very quickly.

Remove the pans from the oven and allow the layers to cool completely before assembling.

Attempting to stack warm layers may cause tearing or sticking.

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Step 13: Prepare the Apricot Jam

Place the apricot jam into a small bowl.

Warm it slightly until it becomes easy to spread. This can be done in a microwave or over gentle heat.

The jam should be smooth and spreadable but not hot.

Warming the jam helps create thin, even layers between the cakes.

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Step 14: Assemble the Layers

Place the green layer on your work surface.

Spread half of the apricot jam evenly across the surface.

Carefully place the plain layer on top and gently press down.

Spread the remaining jam over the plain layer.

Finish by placing the red layer on top.

At this point, you will have three colorful layers separated by thin layers of apricot jam.

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Step 15: Compress and Chill the Layers

Cover the assembled layers with parchment paper.

Place a flat baking sheet or tray on top and add a little weight. This gentle pressure helps the layers bond together and creates the signature dense texture associated with Italian Rainbow Cookies.

Transfer everything to the refrigerator.

Chill for at least 6 hours, although overnight chilling produces the best results.

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Step 16: Prepare the Chocolate Coating

When the layers are fully chilled, melt the bittersweet chocolate together with the vegetable oil.

The oil helps create a smoother coating and makes the chocolate easier to spread.

Stir until completely smooth and glossy.

Allow the chocolate to cool slightly before applying it to the cookies.

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Step 17: Coat the Top With Chocolate

Remove the chilled layered cake from the refrigerator.

Pour the melted chocolate over the top and spread it evenly using an offset spatula.

Work quickly because the chocolate begins setting fairly fast.

For a decorative finish, lightly drag a fork across the surface to create subtle lines.

Return the slab to the refrigerator until the chocolate is firm.

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Step 18: Slice Into Cookies

Using a sharp serrated knife, trim the edges to create clean sides.

Cut the slab into long strips and then into smaller rectangles or squares.

For the cleanest cuts, wipe the knife between slices.

You will reveal beautiful red, white, and green layers separated by apricot jam and topped with a smooth chocolate finish.