1. Add the heavy cream, vanilla extract, and cinnamon to a large mixing bowl and beat on high speed with an electric mixer for about two minutes, or until stiff peaks form when the beater is lifted.
2. Add the sweetened condensed milk and fold it in gently with a rubber spatula until fully incorporated.
3. Add the Snickerdoodle cookie pieces and mix gently with a rubber spatula until combined.
4. Pour the ice cream into an 8×4 metal loaf pan and place in the freezer for a minimum of four hours for soft ice cream, or overnight for hard, more scoopable ice cream
5. Remove the ice cream from the freezer and top with extra Snickerdoodle cookie pieces.
6. Serve in a waffle cone or bowl topped with a dusting of cinnamon.