This holiday-season treat combines the delicate chew of French-style shells with a nostalgic nod to boxed snack cakes. I first developed this idea during an evening of cookie exchanges when I wanted something that looked like a tiny decorated tree but tasted like a grown-up version of a childhood holiday dessert. The shells are lightly almond-forward and the filling is a rich buttercream cut with soft, crumbled Christmas Tree Cake pieces so every bite brings a little surprise of cake crumbs and vanilla-scented butter. The finished sandwiches are bright green, drizzled with white chocolate and dotted with red and green sprinkles, and they make even a crowded dessert table feel curated.

What makes this version special is the pairing: the smooth, meringue-based shells provide structure and a mild, nutty backdrop while the filling gives texture and a familiar cake crumb comfort. I learned to balance the filling so it isn’t overly sweet — a pinch of salt and a modest amount of cream keep it silky and pipeable. These were an instant hit with family and friends the first time I made them; kids loved the sparkles and grown-ups asked for the recipe. If you want a delightful holiday project that rewards precision and creativity, these will become a signature treat.

Ingredients

• Pooled dry for shells: Powdered sugar 1 3/4 cups — sifted twice to remove lumps; using a fine confectioners sugar makes the shells smooth and helps the batter fold without graininess.
• Almond flour: 1 cup finely ground, blanched almond flour — pick a fresh, blanched variety (Bob's Red Mill-style) for the lightest color and no specks that show through green coloring.
• Egg whites: 3 large, room temperature — they whip to greater volume at room temperature; separate them a day ahead and let them come back to room temp if refrigerated.
• Granulated sugar: 1/4 cup — used to stabilize the meringue and produce the characteristic sheen and feet.
• Cream of tartar: 1/2 teaspoon — stabilizes the egg whites and helps prevent overwhipping.
• Green gel food coloring: a few drops — gel provides intense color with less liquid, preserving batter consistency; choose leaf green for a natural tree color.
• Butter for filling: 1/2 cup unsalted, softened — rich and smooth to create a stable buttercream that pipes well.
• Powdered sugar for filling: 1 1/2 cups — sift before combining with butter to avoid lumps in the filling.
• Vanilla extract: 1/2 teaspoon — pure vanilla rounds the filling and pairs nicely with the snack cake crumbs.
• Heavy cream: 2 tablespoons — adds silkiness and helps adjust consistency if needed.
• Crumbled snack cakes: 1/2 cup finely crumbled (Christmas Tree Cakes or similar) — fold gently into buttercream for texture and flavor echoes of the original treat.
• Pinch of salt: for filling — balances the sweetness and enhances flavor perception.
• Decorations: white chocolate for drizzle, red and green sprinkles, edible gold stars (optional) — choose high-quality couverture for a glossy drizzle.

Instructions

Prepare dry ingredients: Measure and sift the confectioners sugar and almond flour together twice into a large bowl. This removes any almond lumps and aerates the mixture so it folds into the meringue cleanly without deflating. Use a fine-mesh sieve and tap gently — about 2 to 3 passes. Whip the egg whites: Place room-temperature egg whites in a clean, grease-free bowl. Beat on medium speed until foamy, then add the cream of tartar. Gradually add granulated sugar over 60 to 90 seconds while increasing speed to high. Whip to stiff, glossy peaks — when you lift the whisk the peak should hold with a slight curve. Overwhipping dries the whites; underwhipping will prevent proper feet. Color the meringue: Add green gel food coloring a drop at a time and fold briefly to distribute color evenly. Use gel to keep batter viscosity intact; aim for a vibrant but not neon green so decorations show up well. Macaronage — fold dry into meringue: Gently fold the sifted almond-sugar mix into the meringue in three additions. Use a spatula and rotate the bowl as you fold; press the spatula against the bowl and scrape through the mixture. Stop when the batter falls in a smooth ribbon and flows like lava — about 20 to 40 folds depending on your speed. If it runs too quickly it is overmixed; if it holds tight peaks it needs more folding. Pipe shapes and rest: Transfer batter to a large piping bag fitted with a plain round tip. Pipe tree shapes or circles onto silicone mats or parchment-lined trays. Tap each tray firmly against the counter twice to release air bubbles and use a toothpick to pop any visible bubbles. Let the shells rest at room temperature for 30 to 60 minutes until a dry skin forms — lightly touch a shell should not leave batter on your finger. Bake: Preheat oven to 300°F (150°C). Bake one tray at a time on the middle rack for 14 to 16 minutes, rotating halfway for even browning. Shells are done when they have feet and the tops are set and slightly glossy. Allow to cool completely on the mat before removing to avoid breaking the delicate surface. Make the filling: Beat 1/2 cup softened unsalted butter until light and fluffy. Add 1 1/2 cups sifted powdered sugar, 1/2 teaspoon vanilla, and 2 tablespoons heavy cream; beat until smooth. Fold in 1/2 cup finely crumbled snack cake and a pinch of salt. Adjust texture with a teaspoon more cream if needed — filling should be pipeable but not runny. Assemble: Pair shells by size. Pipe a dollop of filling onto one shell and gently press its match on top to form a sandwich. Wipe any excess filling for clean edges. Place in a single layer in an airtight container with parchment layering. Decorate and mature: Drizzle melted white chocolate across the tops, add red and green sprinkles, and place an edible gold star on the tip of tree-shaped sandwiches if desired. Refrigerate assembled sandwiches for 24 hours to mature flavor — this step softens the shell interior slightly and allows flavors to meld.

Storage Tips

Store assembled sandwiches in a single layer or in shallow boxes with parchment paper separating layers. Refrigerate in an airtight container; they keep well for up to 5 days. For longer storage, freeze unfilled shells flat or freeze fully assembled sandwiches for up to 3 months — thaw in the fridge overnight to avoid condensation on the shell surface. When reheating gently, let them come to room temperature for 20 to 30 minutes; avoid microwaving which will melt the filling.

Ingredient Substitutions

If you need to avoid nuts, use a 1:1 replacement of almond flour with a blend of superfine oat flour and powdered sugar, though color and texture will shift and shells become slightly less crisp. To make the filling dairy-free, substitute dairy-free butter and coconut cream for heavy cream; note coconut will impart a mild flavor. Swap snack cake crumbs with crushed speculoos or graham crackers for a different flavor profile; reduce quantity by a tablespoon if the crumbs are very dry.

Serving Suggestions

Arrange tree-shaped sandwiches upright in a shallow box lined with tissue or lay them in neat rows on a long platter for a buffet. Pair with coffee or spiced tea to balance sweetness. For a holiday platter, include a mix of plain and decorated versions and label flavors with tiny tags. Garnish with fresh rosemary sprigs for an evergreen look and scatter a few edible gold stars for visual interest.

Cultural Background

These sandwiches merge French meringue technique with a modern holiday-American twist. Macarons themselves have evolved from almond-based confections found across Europe to the refined two-shell sandwich popularized in Paris. The addition of branded snack cake crumbs nods to nostalgic American holiday treats, combining classic pastry technique with seasonal flavors familiar from childhood holiday celebrations.

Seasonal Adaptations

In winter, add a pinch of cinnamon or nutmeg to the filling to echo holiday spice. For a spring variation, tint shells pastel green and swap cake crumbs for light lemon cake with a teaspoon of fresh lemon zest in the filling. For a chocolate holiday version, add 1 tablespoon of cocoa to the shell dry mix and use chocolate ganache drizzle instead of white chocolate.

Meal Prep Tips

Make shells up to 48 hours in advance and keep them in an airtight container at room temperature; fill them the day before serving to allow maturation. Portion filling into a piping bag and refrigerate until assembly time to speed up the process. For gifting, assemble the day before transport and store in a chilled cooler with ice packs to maintain texture during travel.

Success Stories

At my neighborhood cookie swap, these were the most-requested recipe the following year. One friend recreated them for a work party and reported colleagues compared them favorably to bakery macarons. A relative used the same technique to make mini-tree versions for wedding favors, scaling the batch and using edible silver stars for a formal look.

These small sandwiches are as satisfying to make as they are to eat. If you give them a try, take a photo of your decorated trees and share it — I love seeing how bakers personalize the look. Happy baking and happy holidays.