Line two baking sheets with parchment paper and have a pastry bag with a plain tip ready.
Grind together the powdered sugar with the almond powder and cocoa so there are no lumps; use a blender or food processor since almond meal that you buy isn’t quite fine enough.Scrape 1 vanilla bean and add with flour mixture.
In the bowl of a standing electric mixer, place the egg whites in and beat at 4 for 3 minutes. Add sugar and cream of tartar and beat for 3 minutes at 6. Up to 8 and beat for 3 more minutes. Add in flavoring or gels and beat for 1 final minute. At this point you should have a dry meringue.
Carefully fold the dry ingredients, in two batches, into the beaten egg whites with a flexible rubber spatula. When the mixture is just smooth and there are no streaks of egg white, stop folding and scrape the batter into the pastry bag (standing the bag in a tall glass helps if you’re alone).
Pipe the batter on the parchment-lined baking sheets in 1-inch circles (about 1 tablespoon each of batter), evenly spaced one-inch apart.
Rap the baking sheet a few times firmly on the counter top to flatten the macarons, then bake them for 15-18 minutes. Let cool completely then remove from baking sheet.