In a medium saucepan, mix half of the water with the sugar over high heat. Stir continuously for about 3–5 minutes until the sugar completely dissolves.

Once the sugar has dissolved, whisk in the cocoa powder and salt until fully blended. Bring to a gentle boil while stirring for 30 seconds.

Stir in the remaining water and any optional flavor extracts. Let the mix cool slightly, then transfer it to the refrigerator and chill for at least 30 minutes.

If using an ice cream maker, churn according to manufacturer's instructions until soft-serve consistency; otherwise freeze in ice cube trays until solid, about 4 hours, before blending until smooth.

Serve immediately for a soft texture or freeze for 1-2 hours for firmer texture. Let it sit out for 15 minutes before serving for best scooping experience.