Print out 2 copies of the template above. Line a baking sheet with parchment paper. Line the two templates up underneath of the parchment paper.
Sift together the almond flour and powdered sugar. If you can't find almond flour you can always make it with almonds and a food processor. Finely grind the almonds and sift through a fine mesh sifter. Discard or snack on any large pieces.
In a large mixing bowl, add in egg whites. Turn on high and beat until the egg whites form a soft peak meringue.
Add in the granulated sugar, salt, vanilla extract, and cream of tartar. Mix on high until a stiff peak meringue forms. I slowly but constantly add in the granulated sugar into the meringue instead of tossing it all in at once.
Add in the leaf green gel paste color and give it a quick mix to incorporate.
Very lightly and carefully fold in a third of the almond flour/powdered sugar into the meringue with a spatula. Repeat with the rest of the almond flour/powdered sugar mixture. All together you'll want to have about 59 turns of this mixture. If you don't mix enough the macaron shell will be extremely fluffy and cracked. If you over mix, the macaron shell will be extremely flat and might not form a foot.
Preheat oven to 300 degrees.
Fill a piping bag with the macaron shell filling. I used a #12 wilton tip on the end of my piping bag. Pipe macaron shells on the baking sheet following the christmas tree template. Pipe the trunk first and then start from the bottom of the tree and go back and forth to the very top of it. Watch the video below to get a better idea.
Sprinkle a few of the edible golden stars onto the freshly piped macarons.
Let the macarons dry until they are no longer tacky to the touch. It will take 20 minutes to 1 hour.
Place in the oven for about 10 minutes until they no longer stick to the parchment paper.
Let the macaron shells cool.
Match the macaron shells together according to size and shapes that best fit together.
For the Frosting
In a large bowl, add in the butter, powdered sugar, milk, and vanilla. Mix on medium until incorporated. Turn mixer on high and beat for another 1 - 2 minutes until light and fluffy.
Add super red gel paste food color to the frosting. Add enough to give a bright red. Stir to incorporate. Be sure to scrape the bottom of the bowl to get all of the food color.
Place frosting in a piping bag with a small tip. I think I used a #7 Wilton tip.
Pipe the outline of the macarons and fill in the center. Add the top shell.
Store in an air tight container.
To get a deeper color frosting, make it and color it 2 days ahead of time and let it sit in the fridge. The day you plan on using it, remove it from the fridge and let it come up to room temperature. You can whip it again, but it may lighten the color. It's best if just stirred with a spatula.