Queens Park Swizzle

In a pilsner glass muddle mint leaves with .25 ounce of simple syrup; add pebble ice to glass, 3/4 way up the glass; combine remaining ingredients in a shaking tin; add small amounts of ice and shake briefly; pour mixture into iced pilsner glass and ‘swizzle’ to layer the ice evenly; dash bitters in even layer over surface of drink; add additional ice for layered effect. Garnish with mint crown.