Gather all your ingredients for the Gingerbread Macarons. Preheat your oven to 310ºF and line your baking sheets with parchment paper.

In a heatproof bowl, combine the granulated sugar and optional egg white powder. Set this bowl over simmering water and add fresh egg whites, whisking continuously until the sugar dissolves.

Transfer the mixture to a stand mixer and whip on high speed until stiff peaks form, about 5-7 minutes.

Sift the almond flour, powdered sugar, and spices into the bowl, then gently fold into the meringue.

Transfer the batter into piping bags and pipe circular dots on the lined baking sheets.

Allow the macarons to rest at room temperature for 30-60 minutes, until the tops feel dry.

Bake for 15-20 minutes at 310ºF, rotating the trays halfway through.

Let the macarons cool on the baking sheets for 5 minutes before transferring to a wire rack.

In a mixing bowl, cream the softened unsalted butter until fluffy, then add confectioners' sugar and mix.

Blend in molasses, vanilla extract, and spices, adjusting with milk as needed.

Once the shells are cool, pipe gingerbread buttercream onto the flat side of half the shells and sandwich with the remaining shells.

Store in an airtight container for at least 24 hours to enhance flavors before serving.