Penicillin

Muddle the ginger slices in a shaker to release their flavor.

Add the Scotch whiskey, freshly squeezed lemon juice, and honey syrup to the shaker, excluding the Islay Scotch whiskey for now.

Fill the shaker with ice and shake vigorously until well chilled.

Double strain the mixture into a chilled Old Fashioned glass filled with fresh ice.

Gently float the Islay Scotch whiskey on top of the cocktail.

Garnish with a piece of candied ginger for a sweet finish.