Preheat oven to 300 degrees F (150 degrees C).
In a large bowl, sift together the Almond Meal (40 gram) and Powdered Confectioners Sugar (40 gram).
Beat the white of an Egg (1) on low speed using an electric mixer until it is white and frothy, approximately 1 minute.
Gradually add the Caster Sugar (45 gram) 1/4 at a time. When the first addition of sugar has completely dissolved, increase the mixer speed to medium and add until all the sugar has been incorporated. Continue to beat until stiff peaks form.
Add the meringue to the sifted ground almond flour and icing sugar. Using a spatula, start the macaronage process until you get a molten-like mixture that drips down like a ribbon when lifted.
Transfer the batter to a piping bag with a round tip and pipe out macarons. Start with a large circle for the body, and a smaller circle for the head just touching the large circle. This is because the batter will spread and you don't want to end up with a huge oval.
After piping, knock the bottom of the tray against a flat surface to get rid of air bubbles. Let the shells dry for approximately 30 minutes in an air-conditioned room. You should be able to touch them gently with the tip of your finger without them sticking.
Bake in a preheated oven for approximately 10-13 minutes. Let them cool.
Place Caster Sugar (50 gram) and remaining white of the Egg (1), divided] in a metal bowl over a saucepan of simmering water. Whisk continuously until the sugar is dissolved. It is natural for the egg mixture to become thick and sticky.
Beat the egg white mixture using an electric mixer with a whip attachment on medium-high speed until stiff peaks form.
Continue beating at medium-high speed while adding small chunks of Unsalted Butter (75 gram) gradually. It might curdle, but keep beating until the butter is blended in and the buttercream is smooth.
In a separate bowl, beat Cream Cheese (75 gram) in a mixer on medium speed. Scrape the bowl down then mix in the swiss meringue buttercream on low speed until everything is combined.
Add Lemon Juice (3 dash) to bring out the taste of the cream cheese. Chill frosting slightly before using.
Pipe frosting between 2 macaron shells and decorate with Royal Icing (to taste). Serve and enjoy!