Add the cherries and the cherry juice to a blender. Blend until the cherries are chopped.
Add the ice cream and milk and blend until smooth. Add more milk if needed to reach desired thickness.
Divide half of the ice cream mixture between 2 glasses. Drizzle a layer of chocolate syrup into each glass. Divide the remaining ice cream mixture between the glasses. Top with another drizzle of chocolate syrup. Top with whipped cream and cherries. Serve immediately.
Notes
For thicker shakes, use less milk. For thinner shakes, use more milk.