Blend at high speed for no more than 5 seconds.
Pour into a glass, add ice cubes to fill, then add the garnish.
*Donn’s mix: Bring 3 crushed cinnamon sticks, 1 cup of sugar and 1 cup of water to a boil, stirring until the sugar is dissolved.
Simmer for 2 minutes, then remove from the heat and let sit for at least 2 hours before straining into a clean glass bottle.
Then add 1 part of the syrup and 2 parts of fresh grapefruit juice together.