Slice the chili into thin slices. Cut a lemon in half. Combine chocolate liqueur and Black Taffel Aquavit in a shaker. Add the chili slices and the lemon's juice. We recommend purchasing a handheld citrus squeezer. Add the simple syrup and a fresh egg white. Shake the mixture first without ice cubes for ten seconds, to froth the egg white into the drink. A vertical shake of ten seconds is most effective. Separate the shaker. The mixture should look like a thick foam with small bubbles. Add ice. Close the shaker, and shake for ten seconds again to chill and dilute the cocktail. Separate the shaker. Strain the drink into the stemmed glass. Top with cacao nibs.