In a large bowl, whisk together the cocoa powder and sugar.
Add the whole milk and mix until fully combined.
Gradually stir in the heavy cream, mixing well.
Add the vanilla extract and stir until incorporated.
If using, fold in the chocolate chips.
Pour the mixture into an ice cream maker.
Churn according to the manufacturer's instructions until thickened.
Transfer the ice cream to an airtight container.
Freeze for at least 4 hours or until firm.
Serve in bowls or cones and enjoy!