Lightly grease two baking sheets with cooking spray and line with parchment paper. (This helps hold the paper down when piping the macarons.)

To make reindeer shapes: Before making the macaron mixture, make a single template for the reindeer head and antlers. Draw the desired reindeer head and antler shape and size on a piece of parchment paper, then cut it out. Trace the template onto parchment paper, about an inch apart, approximately 12 per baking sheet. Set aside.

To make macarons: Place 4 egg whites in a stand mixer fitted with a whisk attachment. Place granulated sugar and water in a heavy pot and bring to a boil. Once sugar mixture has reached 244° (using a candy thermometer), turn mixer on high speed and slowly pour in sugar-water mixture. Beat on high until white, glossy and thick. Add brown gel coloring and continue beating. While meringue is whipping, sift almond flour and powdered sugar in a large bowl. Add 4 remaining egg whites and fold in until the mixture has a consistency of paste. Slowly add the whipped meringue to the paste and continue to fold in until completely incorporated, making a batter.

Preheat oven to 350°. Spoon macaron batter into a piping bag fitted with a large round piping tip (size 5/8 inch). Pipe all the heads following the template on the parchment paper. With a smaller round piping tip (size 8MM), pipe antlers on each head. Be sure to connect the antlers to the head. When all heads/antlers are piped on the parchment, gently tap the baking sheet on a table top to release air bubbles. Leave at room temperature to dry for about 45 minutes. The macarons should not be sticky when going into the oven. Once shells are dry, bake for 16 minutes. Let macarons cool completely before assembling.

To decorate reindeers: Fill a pastry bag with a small amount of red edible paint. Using a small piping tip (3/8 inch), place a drop in the middle of half of the heads to make the reindeer nose. Sprinkle with edible glitter. Paint the antlers with bronze edible paint and sprinkle with edible glitter. Then paint reindeer eyes and smile. While the edible paint dries, make the buttercream.

To make buttercream: In a stand mixer with paddle attachment, beat butter and powdered sugar on low until incorporated. Turn mixer up to medium-high and beat until light, fluffy and white in color. Add desired flavoring or extract and mix until incorporated.
To assemble macarons: Pipe or spoon a small amount of buttercream on half of the macarons. Top each with one of the decorated reindeer head macarons. Pour sprinkles onto plate. Roll the edges of each macaron in sprinkles.

*NOTE: Edible paint, glitter and piping bag can be found online or at DIY stores.