In a large mixing bowl, pour in the heavy cream. Whisk or use a hand mixer to whip the cream until soft peaks form. This step helps create that fluffy, soft texture we all love in ice cream.

Add the whole milk, sugar, and vanilla extract to the whipped cream. Gently fold everything together until the sugar dissolves and the mixture is smooth.

Be careful not to deflate the whipped cream too much—you want to keep it light and airy.

In a small bowl, combine the cocoa powder and hot water. Stir until the mixture forms a smooth, thick paste. If you’re using melted chocolate, you can skip this step and melt your chocolate in the microwave or over a double boiler.

Pour half of the vanilla base into your freezer-safe container. Drizzle half of the chocolate mixture over the top. Then, add the remaining vanilla base and drizzle the rest of the chocolate.

Use a butter knife to gently swirl the chocolate and vanilla together. Don’t overmix, you want those distinct swirls to stay visible.

Cover the container tightly with a lid or plastic wrap. Place it in the freezer for 4–6 hours, or until the ice cream is firm but scoopable.

When you’re ready to serve, let it sit at room temperature for 5–10 minutes for easier scooping. Enjoy your creamy marble ice cream!