From The Hitchhiker's Guide to the Galaxy by Douglas Adams
1 part Everclear (or any other strong grain alcohol such as Bourbon, Moonshine, or Vodka)
1 part Bitter Lemon (or plain Tonic Water)
1 part Bombay Sapphire Gin (or other gin)
1 part Yukon Jack Perma-Frost Schnapps (or other mint schnapps, or white crème de menthe)
Enough blue food coloring to make the mixture a very light sky blue
Yellow food coloring (optional)
Mix the first five ingredients and chill. Then, take a sugar cube and let it absorb 1 milliliter of cinnamon extract and 1 drop of yellow food coloring (optional). Place three ice cubes in a glass and pour the chilled liquid mixture over these. Drop in the sugar cube and stir to dissolve, or just let it sit (if food coloring is used, often the sugar cube is just left to sit, to create a layering effect with the color). Sprinkle the Angostura Bitters in the drink, and add an olive. Drink, but very carefully.