This is so dangerous, I haven’t dared try it. It’s considered to be a “hot toddy.”
1 t sugar
2 oz boiling water
2 oz Scotch, heated
Heat two large mugs. In one, dissolve the sugar in the boiling water. In the other, place the heated Scotch and (carefully!) ignite with a match. Dim the lights and pour the contents back and forth between the mugs to create a stream of blue flame between them. Once the flames die out, add a twist of lemon and a dash of cinnamon.