Special equipment: a cocktail shaker
For the simple syrup: Put the sugar and 1/2 cup water in a saucepan, bring to a boil and stir to dissolve the sugar. Cool before using. The syrup will keep covered, in the refrigerator, for 1 week.
For the sour: Put the Galliano, lemon juice, grappa, honey and 1 1/2 teaspoons simple syrup in an ice-filled cocktail shaker and shake vigorously. Strain into a cocktail glass and enjoy.