Step 1: Melt the Butter and Heat the Cream

In a medium saucepan over medium heat, combine the heavy cream and unsalted butter. Stir occasionally until the butter is fully melted and the mixture is warm, but not boiling.

Step 2: Add Sugar and Cocoa Powder

Whisk in the granulated sugar, brown sugar, and unsweetened cocoa powder. Stir continuously until the sugar is fully dissolved, and the mixture becomes smooth.

Step 3: Simmer and Add Chocolate Chips

Reduce the heat to low and add the chocolate chips. Stir constantly until they are fully melted into the sauce, creating a rich, glossy consistency.

Step 4: Enhance with Vanilla and Salt

Remove the saucepan from the heat and stir in the vanilla extract and salt. This enhances the chocolate flavor and balances the sweetness.

Step 5: Serve or Store

Let the hot fudge sauce cool for a few minutes before using. If storing, pour it into a heatproof jar and keep it in the refrigerator for up to two weeks.