First, make the ginger syrup. Put the sugar, ginger, cinnamon, lemon peel and a pinch of black pepper in a pan with 50ml water and bring to a simmer (watch closely, as it can bubble up). Stir once or twice until the sugar has dissolved. Turn off the heat and leave to infuse until cold.
Strain through a fine mesh sieve and discard the lemon peel. Pour the syrup into a 500ml bottle along with all the alcohol and 100ml cold water. Shake and chill until needed.
To gift, package up the cocktail base and the instructions: Chill, then divide between four chilled glasses and serve straightaway. The cocktail base will keep chilled for three days.