Combine the gin, vermouth, simple syrup, and luster dust in a cocktail shaker.
Add a big scoop of ice and shake vigorously for at least 20 seconds.
Place 1 or 3 cocktail onions in the bottom of each glass. Strain the martini into glasses. Garnish with a rosemary sprig.
The rosemary simple syrup brings a little sweetness and deeper woodsy notes. But it can be skipped if preferred to avoid the sweetness.The rosemary sprig has several purposes: garnish, adds additional woodsy notes, and to stir (see below).The cocktail onions are a nod to winter, looking like snowballs, while also representing the Gibson. If you choose to use the onions, you may want to skip the simple syrup and instead, place a small piece of rosemary in the cocktail shaker to impart the woodsy flavor in the drink itself.The luster dust is beautiful but will settle if it sits for too long. Simply stir with the rosemary sprig to reactivate the swirling!I like to freeze my glasses to give it an extra "frosted" feel and to help keep the drink cool. The frosted look disappears relatively quickly.Luster dust, pearl dust, and edible glitter are all technically different things however I have found manufacturers sometimes use any of those names. Ultimately you are aiming for a shimmering dust that is almost cloudy (versus not shimmering or solid glitter without the cloud). The ingredient link above works perfectly!Bartending superstition believes cocktail onions should only be used in odd numbers (1 or 3) for good luck.