Pour a thin layer of sugar onto a small plate larger than the rim of your martini glass.

Prepare martini glass by lightly rubbing the rim with the fleshy wet part of a cut lemon to dampen it, then dip the moistened rim of the glass into the sugar, gently shaking off any excess.

Combine all ingredients except for sugar in a cocktail shaker and shake vigorously.

Strain into the prepared martini glass. Garnish with a slice of lemon and serve immediately.