Add coffee grounds and water to a large pitcher. Stir. Cover and let sit at room temperature overnight for up to 12 hours.
Strain mixture through a coffee filter or cheesecloth. Discard leftover coffee grounds. Store coffee in fridge until ready to use.
Fill a large glass with ice cubes. Add coffee, vanilla syrup, and half and half. Stir to combine. Taste and adjust half-and-half and/or vanilla cinnamon syrup as needed.
In a small saucepan over medium-high heat, add sugar, water and vanilla bean. Bring to a roiling boil and remove from heat. Let cool, then stir in vanilla extract and cinnamon.
Pour syrup through a fine mesh sieve to remove any vanilla bean pieces. Store in an airtight container in the fridge for up to two weeks.