In a large mixing bowl, combine the granulated sugar and cocoa powder. Whisk them together until well blended.
Pour in the heavy cream, whole milk, vanilla extract, and salt. Whisk the mixture for about 2-3 minutes until smooth.
Cover the bowl with plastic wrap and refrigerate the mixture for at least 2 hours or overnight.
If using an ice cream maker, pour the chilled mixture into the ice cream maker and churn according to the manufacturer’s instructions.
If you don't have an ice cream maker, pour the mixture into a shallow dish and place it in the freezer. Stir vigorously with a fork every 30 minutes for about 2-3 hours.
Transfer the ice cream into an airtight container, smooth the top, cover, and freeze for at least 4 hours.