This holiday I fell in love with a playful twist on a classic: delicate French-style shells colored a deep evergreen and filled with a buttercream that hides finely crumbled Christmas tree snack cake. I first developed this combination on a cold December evening when I wanted something elegant for a small family gathering but with the familiar, nostalgic flavors of holiday snack cakes. The result is light, crisp shells that give way to a soft, buttery center punctuated by little pockets of cake crumbs for texture. They look spectacular on a platter and taste even better after they rest, when the flavors meld into a creamy, spongy bite.

What makes these special is the contrast of textures and the joyful presentation. The shells are crisp on the outside with a faint chew inside, colored a festive green that keeps the focus on the holiday theme without overpowering the palate. The buttercream is fluffy and just sweet enough, with the added crumbed cake lending a gentle, cake-like structure and a hint of spice if you choose a seasonal variety. I love making these for cookie exchanges because they travel well when chilled and always spark conversations. Over the years I have learned subtle techniques to get consistently smooth feet and perfectly round or tree-shaped tops, and I share those here so you can recreate them with confidence.

Ingredients

• Powdered sugar (for shells): 1 3/4 cups. Use a fine, siftable powdered sugar like Domino to avoid lumps; sifting twice prevents gritty shells and helps the almond flour incorporate smoothly.
• Almond flour: 1 cup, finely ground and blanched. Bob's Red Mill Super-Fine or almond flour labeled "blanched" gives the best texture and reduces speckling in the shells.
• Egg whites: 3 large, room temperature (about 90 g total). Bring to room temperature for better volume when whipping; separate carefully to avoid yolk contamination.
• Granulated sugar: 1/4 cup, to stabilize the meringue and give structure to the shells.
• Cream of tartar: 1/2 teaspoon, an acid that helps stabilize egg white foam and produces taller peaks.
• Green gel food coloring: a few drops to reach the desired evergreen hue; gel color is concentrated and will not alter batter consistency like liquid coloring.
• Unsalted butter: 1/2 cup, softened for the filling. Use good-quality butter like Plugra or Kerrygold for a rich flavor.
• Powdered sugar (for filling): 1 1/2 cups, sifted into the butter to ensure a smooth buttercream.
• Vanilla extract: 1/2 teaspoon, pure vanilla enhances the creamy notes in the filling.
• Heavy cream: 2 tablespoons, for loosening the buttercream to pipe smoothly.
• Crumbled snack cakes: 1/2 cup, finely crumbled Christmas Tree Cakes or a similar holiday snack cake to add a cake-like interior texture.
• Pinch of salt (for filling): balances sweetness and lifts flavors in the buttercream.
• White chocolate drizzle, sprinkles, edible gold stars: optional for finishing and visual appeal.

Instructions

Prepare dry ingredients: Sift 1 3/4 cups powdered sugar and 1 cup almond flour together twice into a large bowl. Sifting removes lumps and aerates the mix so it blends into the meringue without deflating. Set aside while you make the meringue. Whip egg whites: In a clean, grease-free bowl, beat 3 room-temperature egg whites until foamy, then add 1/2 teaspoon cream of tartar. Gradually add 1/4 cup granulated sugar and continue to beat until stiff, glossy peaks form. The meringue should hold shape and feel satiny; overbeating will dry it out and underbeating will prevent structure. Color and fold: Add a small amount of green gel coloring into the meringue and fold to incorporate. Gently fold the almond-powdered sugar mixture into the meringue in two or three additions using a spatula. Use the macaronage technique: scrape the bowl and fold until the batter flows like lava and forms a ribbon that dissolves back into the batter in about 8 to 12 seconds. Pipe shells: Transfer batter to a piping bag fitted with a medium round tip. Pipe tree shapes or circles onto baking sheets lined with silicone mats or parchment. If piping trees, pipe a narrow trunk followed by a layered triangle for branches. Tap trays firmly against the counter to release air bubbles. Rest trays for 30 to 60 minutes until a thin skin forms and the tops are not tacky to the touch. Bake shells: Preheat the 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 color. The shells are done when they lift easily from the mat and have developed feet. Cool completely on the baking sheet before removing to avoid cracking. Make the filling: Beat 1/2 cup softened unsalted butter until light and fluffy, then gradually add 1 1/2 cups powdered sugar, 1/2 teaspoon vanilla, 2 tablespoons heavy cream, and a pinch of salt. Beat until smooth. Fold in 1/2 cup finely crumbled snack cakes until distributed but not completely dissolved—small crumbs create a pleasing texture. Assemble: Pair shells of similar size. Pipe the filling onto one shell and sandwich with the matching shell, pressing gently to spread the filling to the edge. For tree-shaped shells, pipe strategically so the layers align and the tree silhouette remains clear. Decorate and mature: Drizzle with melted white chocolate, add red and green sprinkles and top with an edible gold star if desired. Refrigerate in an airtight container for 24 hours to mature; this step harmonizes the flavors and softens the filling slightly for the perfect bite.

Storage Tips

Keep finished sweets in a single layer in an airtight container lined with parchment to prevent sticking. Refrigerate for up to five days; for longer storage freeze them in a single layer on a tray for two hours, then transfer to a freezer-safe container separated by parchment. Thaw overnight in the refrigerator to avoid condensation forming on the shells. When reheating for serving, bring to room temperature for 20 to 30 minutes—this softens the buttercream without making the shells too soft. Indicators of freshness include a bright color, a stable filling, and crisp edges on the shells.

Ingredient Substitutions

If you need a nut-free version, replace almond flour with a fine oat flour blend and swap the snack cake for a gluten-free alternative, but expect different texture and color. For a dairy-free filling, use a vegan butter substitute and coconut cream in place of heavy cream; flavor will be slightly coconut-forward. If you cannot find Christmas Tree Cakes, use any lightly spiced snack cake or even crumbled gingerbread for a bolder holiday note. Reduce the crumb quantity slightly if your cake is more moist to avoid a loose filling.

Serving Suggestions

Arrange these on a tiered platter with sprigs of fresh rosemary to mimic miniature trees, and pair with mulled wine or hot cocoa for a cozy dessert course. For a cookie exchange, package in small boxes with tissue and a ribbon—these travel well chilled. They also make excellent favors at holiday events; add a small sticker with the flavor note for guests with allergies.

Cultural Background

Macarons are a French confection with a long tradition of refinement. This variation blends that technique with American holiday snack culture by incorporating a commercially made tree-shaped cake into the filling. The idea celebrates both the precision of European desserts and the comfort of nostalgic packaged treats, creating a hybrid that feels festive, familiar, and just a bit elegant.

Seasonal Adaptations

Swap green coloring for soft pastel shades for spring celebrations, or use red and white piping for Valentine-themed sweets. In winter, choose spiced snack cakes or add a pinch of cinnamon to the filling. For a New Year’s celebration, finish with edible silver leaf instead of gold stars for a glamorous touch. Small adjustments to the filling fat or crumb ratio can accommodate seasonal flavorings without changing the shell technique.

Meal Prep Tips

Make shells a day ahead and store flat in a single layer, then prepare filling the next day and assemble in the afternoon. Use small plastic containers with compartments if transporting for parties; keep chilled and assemble final decorations on-site to avoid melting sprinkles. Label containers with the make date and any allergen notes so hosts know how long they will remain at peak quality.

These festive treats capture both the joy of holiday baking and the refined technique of classic shell-making. Try them, and let the macarons become part of your seasonal traditions—small, celebratory bites that bring people together.