Prepare the Ice Cream Mixture: In a mixing bowl, combine the heavy cream, whole milk, sugar, and vanilla extract. Stir until the sugar is dissolved and the mixture is smooth. If you want to add flavorings like cocoa powder or fruit purees, mix them in at this stage.
Fill the Ice Cream Ball: Pour the ice cream mixture into the inner compartment of the ice cream ball. Seal the compartment tightly.
Prepare the Outer Compartment: In the outer compartment of the ice cream ball, add ice and rock salt. The ice should fill the compartment, and the salt will help freeze the mixture inside.
Shake the Ball: Seal the ball and shake it vigorously for about 10-15 minutes. You can roll the ball back and forth or pass it between two people for a fun team effort.
Check the Ice Cream: After 10-15 minutes of shaking, open the ice cream ball to check if the ice cream has frozen to your desired consistency. If it's not fully frozen, continue shaking for another few minutes.
Serve and Enjoy: Once the ice cream reaches the right consistency, serve it immediately or transfer it to a container to store in the freezer for later.