Rub lemon around the rim of the glass, then dip into a dish of sugar. In front of and alcohol burner or sterno, rotate the glass over the flame to carmelize the sugar. Place spoon on glass to prevent cracking. Warm brandy in a pan or a chafing dish. Pour into glass and ignite. Add jigger of Kahlua and ignite. Pour in hot coffee, leaving about 1 1/2". Add whipped cream, level to the top of the glass.