Begin by chilling your martini glass, either store in freezer before-hand or fill with crushed ice and add some cold water to fill and allow to cool.
Add all of your ingredients to a shaker and fill with lots of dry, cubed ice.
Shake well and hard for around 8-12 seconds, your cocktail tin should frost over, you want this drink to be ice cold.
Fine strain the mixture into your empty, chilled martini glass.
«Mix some cinnamon powder with crushed digestive biscuits and brown sugar using enough powder to give off a cinnamon aroma. Wet the rim of the glass with lime juice and dip the rim in the biscuit mix.»