Gather all your ingredients for the hot fudge sauce.

In a medium saucepan, whisk together cocoa powder and granulated sugar.

Add butter and heavy cream to the saucepan over medium-low heat, stirring gently.

Continue stirring until the mixture is smooth and glossy, about 3 to 5 minutes.

Remove from heat and stir in vanilla extract and a pinch of salt.

Serve warm or let cool slightly before storing in an airtight container.