Make the clarified butter by melting butter over medium low heat until hot and foamy but not boiling. Skim and discard the white milk solids that form off the top.
In the bowl of a food processor or blender add your egg yolks along with the lemon juice, salt and pinch of cayenne pepper. Blend at high speed for two minutes.
With the blender still running, slowly drizzle in the hot clarified butter. Discard any remaining milk solids.