Sift together almond meal and powdered sugar. Do this sifting thrice, this will make sure that the macarons have a smooth top.
Meanwhile separate the egg whites, the eggs separate best when they are cold. Keep at egg whites at room temperature for 30-45 minutes before you start working on them.
Once the egg whites are at room temperature start beating them using the wire whisk attachment of your stand mixer or using your hand mixer. When it begins to foam, add cream of tartar.
Keep beating till it reaches a shaving foam like consistency and then add the granulated sugar. Beat more till the egg whites develop stiff peaks.
Add yellow color to the egg whites and mix till it's uniformly dispersed.
Fold the almond meal - powdered sugar mixture into the egg whites using a spatula. Don't add the entire thing in one go, do it in 3-4 parts.
Do not undermix and do not overmix either. The batter shouldn't be runny but should still fall down from the spatula in a blob.
Transfer the batter to a pastry bag fitted with 1/2 inch round tip. Pipe the batter onto the sheet/mat making small blobs around an inch big.
After you have piped all the macarons, let them sit at room temperature for 30 minutes, do not bake them immediately.
After 30 minutes put them to bake in a preheated oven at 300 F degrees for around 20 minutes.
Filling
Beat together room butter and cream cheese till smooth and well combined.
Add powdered sugar 1/2 cup at a time and mix till creamy.
Add lemon zest, lemon juice and mix till combined.
Add yellow color [optional] and beat till the filling is smooth and creamy.
Once the macaron shells have completely cooled, fill a pastry bag with the filling.
Pipe little filling in the center of one shell and cover with another macaron shell to make the sandwich cookie.