Many (many) years ago I was a cocktail barman at a large 5 star Hotel in London. Most probably before many of the readers of this were born.
Whilst there I was asked by the hotel manager to see if I could concoct some interesting drinks, so here goes with one I created:
It was quite a hit with the ladies.
Equal measures of Vodka and any clear orange Liqueur, but not any amber coloured. I used Cointreau.
Lump of sugar (preferably square)
Also require small fork (warmed) and a way to light the drink.
Schooner glass (warmed)
Take the warm Schooner glass and mix the above spirits. At the table (if serving in a Restaurant) or on the bar if serving there, place lump of sugar on the fork. Light the drink and place fork directly over the glass (in effect resting on it).
The effect (especially in a soft lit bar) does attract the eye. The blue flame licks up through the fork and caramelises the sugar. This then (as a brown molten liquid) drops into the alcohol below causing it to turn amber in colour while the effect of the heat of the sugar is to cause a crackling noise as it drops into said liquid, with caramelised crunchy sugar descending through the drink before resting at the bottom. Initially, as the sugar descends it leaves a trail of amber streaks in the clear liquid.
Finally, place a mat over the drink to stop the flames and place in front of guest for drinking.
The key is always to have warmed glass and fork. if they are cold it can go wrong as the energy (heat) from the flames is expended, to a great extent, warming the fork first.
Stop taking it all so seriously, none of us get out alive anyway