Prepare the Glass: If desired, rim the glass with a mixture of ground cinnamon and sugar. To do this, lightly wet the rim of the glass with a bit of cream, then dip it into the cinnamon-sugar mixture.
In a cocktail shaker filled with ice, combine the RumChata, vanilla vodka, cinnamon whiskey, and cream.
Shake well until the mixture is chilled and smooth.
Strain the mixture into a chilled cocktail glass.
Garnish (Optional): Garnish with a sprinkle of ground cinnamon and a few cookie crumbles on top. Add a cinnamon stick for an extra touch of spice.
Serve with a snickerdoodle cookie for dipping!