Combine 1 cup granulated sugar and 1 cup water in a small saucepan over medium heat. Stir until sugar dissolves and mixture comes just to a simmer. Add 2 tablespoons dried culinary lavender, reduce heat to low, and simmer gently for 3 minutes to infuse. Remove from heat, cover, and let steep for 20 minutes. Strain through a fine mesh sieve or cheesecloth into a clean jar, pressing on the lavender to extract liquid. Let cool completely. Refrigerate; syrup keeps about 2 weeks.

Cocktail

Dry shake (if using egg white)

If using egg white, add 1 egg white, 2 oz gin, 0.75 oz fresh lemon juice, 0.5 oz elderflower liqueur, and 0.5 oz lavender simple syrup to a cocktail shaker without ice. Dry shake vigorously for 15–20 seconds to emulsify and build foam.

Wet shake

Add a generous handful of ice to the shaker (or, if you skipped the dry shake, add ice and all liquid ingredients now). Shake hard for 12–15 seconds until the shaker is cold to the touch and well chilled.

Strain

Double-strain the cocktail into a chilled coupe or Nick & Nora glass using a Hawthorne strainer and a fine mesh strainer to remove ice shards and any lavender bits.

Garnish and finish

Garnish with a lavender sprig or a lemon twist. Optionally, sprinkle a pinch (about 1 tsp) of edible dried lavender buds onto the foam. Serve immediately.