Prepare a baking sheet by lining it with parchment paper. If you choose to make a template to follow, make for rows of four circles with a pencil. Flip the parchment paper over so the pencil doesn't get into the food.
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, and cream of tartar. Mix on high until a stiff peak meringue forms.
Very lightly and carefully fold in a third of the almond flour/powdered sugar into the meringue with a spatula. All together you'll want to have about 65-75 turns of this mixture including turning in the root beer extract. 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.
Repeat with the rest of the almond flour/powdered sugar mixture.
Add in the root beer extract.
Preheat oven to 300 degrees.
Fill a piping bag with the macaron shell filling. I just used a coupler on the end of my piping bag. Pipe macaron shells on the baking sheet.
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 18 minutes until they no longer stick to the parchment paper.
Let the macaron shells cool.
Place the white chocolate chips in a microwave-safe bowl and place in the microwave for 30 seconds. Stir. Repeat for another 30 seconds. Stir. Repeat if needed until the white chocolate is smooth.
Place the chocolate into a piping bag and pipe onto the shells. Let the cookies set up.