Measure the ice cream into a blender. Add the blueberries, cinnamon, and about half of the milk. Blend.
Add more milk if needed. Blend well until everything is mixed and the blueberries are well blended in.
Pour into galsses and top the Blueberry Milkshake with some whipped cream and any toppings (extras) you might like to use.
Notes
If you are using frozen blueberries you may need to add more milk than suggested in the recipe. Depending on the sweetness of the berries you may wish to add a bit of sugar to the milkshake.